Answer:
The distance the mass would stretch it is 
The correct option is A
Explanation:
From the question we are told that
The period of the slit is 
The acceleration due to gravity is 
Generally the period is mathematically represented as

Whee m is the particle and k is the spring constant
making
the subject
The weight on the particle is related to the force stretching the spring by this mathematical relation


where x is the length by which the spring is stretched

Substituting the equation above for 
![[\frac{T}{2 \pi} ]^2 = \frac{x}{g}](https://tex.z-dn.net/?f=%5B%5Cfrac%7BT%7D%7B2%20%5Cpi%7D%20%5D%5E2%20%3D%20%5Cfrac%7Bx%7D%7Bg%7D)
making x the subject
![x = g [\frac{T}{2 \pi} ]](https://tex.z-dn.net/?f=x%20%3D%20g%20%5B%5Cfrac%7BT%7D%7B2%20%5Cpi%7D%20%5D)
Substituting the value
![x = 9.8 * [\frac{0.2}{2 * 3.142} ]^2](https://tex.z-dn.net/?f=x%20%3D%209.8%20%2A%20%5B%5Cfrac%7B0.2%7D%7B2%20%2A%203.142%7D%20%5D%5E2)
