By changing width task environment is not working properly

Question

I am working in extbookdocument class. I prepared my book with setting width size 7 inches by using the command

\usepackage[paperheight=9in,paperwidth=7in,top=1in,bottom=1in,right=1in]{geometry}

But if I change my width size to 6 inches then task environment is NOT giving required output.

My code is

    ...
    \usepackage[paperheight=9in,paperwidth=7in,top=1in,bottom=1in,right=1in]{geometry}
    ...

    \NewTasks[counter-format = {\bf tsk[1].},label-width=24pt]{numbering}[\op]

    ...

    \section{Answers}
    \begin{numbering}(5)
    \op (C)
    \op (A)
    \op (C)
    \op (A)
    \op (B)
    \op (D)
    \op (D)
    \op (C)
    \op (A)
    \op (D)
    \op (C)
    \op (A)
    \op (A)
    \op (C)
    \op (B)
    \op (D)
    \op $\pm2$, $\pm\sqrt2$
    \op*(3) $(q-s)^2-rqp-rsp+sp^2+qr^2$
    \op\SetTaskNumber{21} (D)
    \op (B)
    \op (A)
    \op (C)
    \op (C)
    \end{numbering}
...

The ouput of this code is perfecly alright but if I change the width size to 6 inches the output is not good. I am sharing both outputs. Please tell me what alterations do I need to do if I want the same as it is in the width of 7 inches.

I use font size 10 pt for 7 inches width and 9 pt for 6 inches width by using the command \documentclass[10pt,a4paper]{extbook}.