i think the ans ia a)

 

bcoz .........

let mass of a=m1

let mass of b=m2

now initial vel of both=u

final vel of both=0

change in k.e =change in p.e

therefore

for a

1/2*m1*(-u^2)=-m1*g*h1                           h1=dist travelled by a

u^2/2=gh

h=u^2/2g

 

for b

1/2*m2*(-u^2)=m2*g*h2                             h2=dist travelled by b

 

simplifying

 

h2=u^2/2g

 

therefore h1=h2