Answer:
a

b
Explanation:
From the question we are told that
The total mass of three people is 
The mass of the car is 
The compression of the car spring is 
Generally the spring constant is mathematically represented as

Here F is the force exerted by the mass of three people and that of the car , this is mathematically represented as
=> 
=> ![F = ([2.0*10^{2} ]+[ 1.200*10^{3}]) * 9.8](https://tex.z-dn.net/?f=F%20%3D%20%28%5B2.0%2A10%5E%7B2%7D%20%5D%2B%5B%201.200%2A10%5E%7B3%7D%5D%29%20%2A%209.8)
=> 
So

=> 
Generally if the mass which the car is loaded with is 
Then the force experienced by the spring is
=> 
=> 
=> 
Generally from the above formula the compression is

=> 
=>