A vertical string, suspended from a fixed point and having a small mass attached to the free end is set into oscillations. Which of the following statements about the system are correct?

i. The potential energy of the mass is a minimum at the middle of the swing

ii. Its kinetic energy is a maximum at the middle of the swing

iii. The sum of the potential and kinetic energies is constant throughout the swing

A. i, ii and iii
B. i and ii only
C. ii and iii only
D. i and iii only

Correct Answer: Option C

C. ii and iii only