Let the height of the pool be “h”, and the rise of the water level be “x” , then according to the question , we can write as follows : –
Final volume- Initial Volume= Displacement of water by 150 men
$90 \times 40 \times (h+x) - 90\times40\times x= 150 \times 8 \hspace{1mm} m^3$
Solving the equation above for “x” will give 33.33 cm
So,option B is right