Correct option is B
Given:
AB = 15 cm, BC 20 cm and AC = 25 cm
BP is perpendicular on AC.
Solution:
Since, 15, 20, and 25 Pythagorean triplet the triangle is a right-angle triangle.

We know that,
AP = AB2/AC
=> AP = 152/25 = 9cm
PC = BC2/AC
=> PC = 202/25 = 16cm
BP = (AB × BC)/AC
=> BP = (15 × 20)/25 = 12cm
Area of ΔAPB = (AP × BP)/2
=> 9 × 12/2 = 54cm2
Area of ΔBPC = (BP × PC)/2
=> 12 × 16/2 = 96cm2
Difference between the area of both triangles,
=> 96 - 54 = 42cm2
∴ The correct answer is 42cm2.