The kinetic energy of the pendulum bob in figure 15-1 increases the most between locations a. a and b b. a and c c. b and d d. c and d

 A and C

Explanation:

 Kinetic energy of a body is given by the expression, , where v is the velocity and m is the mass of body.

 In case of a simple pendulum the maximum velocity is at it's stationary position.

So maximum velocity i at position C, which means maximum kinetic energy is at position A.

The velocity of pendulum reduces as the angle between vertical stationary and current position increases.

 So, velocity at E and A are the minimum, so at A and E the kinetic energy value is minimum.

 Now examining the options given, we will understand the kinetic energy increase is maximum in case of A and C.

it is very well related to a lot of things but with my limited knowledge i can confidently say that the answer is space.