How to force first paragraph indentation in exam class

I’m using the exam.cls and after question, i have some description before going into part.

How do i add an indent for the first line of the question?
I’ve tried indentfirst package, hspace{}, itemindent, parindent and these didnt work.

documentclass[addpoints, a4paper, 12pt]{exam}
usepackage{setspace, amsmath, pdfpages, mathtools}
usepackage{times}
pagestyle{headandfoot}
setstretch{1.3} 

setlength{rightpointsmargin}{2.5cm}
cfoot[thepage]{thepage} % page numbering
qformat  % Format for question
{
    textbf{QUESTION thequestion{} (pointsofquestion{thequestion} marks)} 
    hfill
    vrule depth 1.7em width 0pt
}

pointsdroppedatright % enable points at the right margin
marksnotpoints
marginpointname{ points}


% To adjust questions margins
renewcommand{questionshook}{%
  setlength{leftmargin}{0pt}%
    setlength{labelwidth}{-labelsep}%
  setlength{itemsep}{1em}
}

% To adjust parts margins
renewcommand{partshook}{%
  setlength{leftmargin}{1.4cm}%
  setlength{labelsep}{1cm}
  setlength{labelwidth}{0cm}%
  setlength{itemsep}{1em}

}

begin{document}

begin{questions}

question
bla bla bla bla blab bla bla bla bla bla blab bla bla bla bla bla blab bla bla bla bla bla blab bla bla bla bla bla blab bla bla bla bla bla blab bla bla bla bla bla blab bla 

begin{parts}

    part[5]
    bla bla bla bla blab bla bla bla bla bla blab bla bla bla bla bla blab bla bla bla bla bla blab bla bla bla bla bla blab bla bla bla bla bla blab bla bla bla bla bla blab bla 
    
    droppoints 
    
    part[4]
    bla bla bla bla blab bla bla bla bla bla blab bla bla bla bla bla blab bla bla bla bla bla blab bla bla bla bla bla blab bla bla bla bla bla blab bla bla bla bla bla blab bla 
    
    droppoints 

end{parts}

end{questions}

end{document}

Thanks in advance.

documentclass[addpoints, a4paper, 12pt]{exam}

setlength{rightpointsmargin}{2.5cm}
cfoot[thepage]{thepage} % page numbering
qformat  % Format for question
{%
    textbf{QUESTION thequestion{} (pointsofquestion{thequestion} marks)} 
    hfill
    vrule depth 1.7em width 0pt
}

pointsdroppedatright % enable points at the right margin
marksnotpoints
marginpointname{ points}


% To adjust questions margins
renewcommand{questionshook}{%
  setlength{leftmargin}{0pt}%
    setlength{labelwidth}{-labelsep}%
  setlength{itemsep}{1em}%
  letoldquestionquestion% Copy question into oldquestion
  renewcommand{question}{%
    oldquestion% Default question style
    hspace*{1.5em}ignorespaces% Insert paragraph indent/space
  }%
}

% To adjust parts margins
renewcommand{partshook}{%
  setlength{leftmargin}{1.4cm}%
  setlength{labelsep}{1cm}
  setlength{labelwidth}{0cm}%
  setlength{itemsep}{1em}

}

begin{document}

begin{questions}

  question
  bla bla bla bla blab bla bla bla bla bla blab bla bla bla bla bla blab bla bla bla bla bla blab bla bla bla bla bla blab bla bla bla bla bla blab bla bla bla bla bla blab bla 

  begin{parts}

    part[5]
    bla bla bla bla blab bla bla bla bla bla blab bla bla bla bla bla blab bla bla bla bla bla blab bla bla bla bla bla blab bla bla bla bla bla blab bla bla bla bla bla blab bla 
    
    droppoints 
    
    part[4]
    bla bla bla bla blab bla bla bla bla bla blab bla bla bla bla bla blab bla bla bla bla bla blab bla bla bla bla bla blab bla bla bla bla bla blab bla bla bla bla bla blab bla 
    
    droppoints 

  end{parts}

end{questions}

end{document}