Option A $\quad 24 \mathrm{~N} \mathrm{~s}$
Option B $\quad 20 \mathrm{~N} \mathrm{~s}$
Option C $\quad 12 \mathrm{~N} \mathrm{~s}$
Option D $\quad 6 \mathrm{~N} \mathrm{~s}$
Solution:
The correct option is C
Change in momentum is given as $\Delta \mathrm{p}$
$\Delta \mathrm{p}=$ Area of $\mathrm{F}-\mathrm{t}$ graph
$=\frac{1}{2} \times 2 \times 6-3 \times 2+4 \times 3$
$=12 \mathrm{~N}-\mathrm{s}$