Answer:
d) decreased by a factor of the square root of 3
Step-by-step explanation:
Data provided in the question
Mass = M on a spring
Spring constant = k
Period = T
Spring constant = 3k in the case when the same mass is hung
Based on the above information, the period of the motion is
As we know that

Based on this, there is a decrease by a factor of the square root of 3
hence, the correct option is d.