C. 0.125 ×10^-3 m
This question was addressed to me during an online exam.
This intriguing question originated from Elasticity topic in section Thermal Properties of Matter of Engineering Physics I
Explanation: Young’s modulus = (Force ×Length)/(Area ×Elongation); Area=πr^2
Elongation = (Force ×Length)/(Area ×Young’s modulus)
Elongation = 15.9mm.