They all move through empty space at the speed of light
Benthos
Option b is the answer
Answer:
Explanation:
Given
time taken 
Speed acquired in 2 sec 
Here initial velocity is zero 
acceleration is the rate of change of velocity in a given time


Distance travel in this time

where
s=displacement
u=initial velocity
a=acceleration
t=time


so Jet Plane travels a distance of 42 m in 2 s