A particle starts its motion from rest under the action of a constant force. If the distance covere in first 10 seconds is $S_1$ and that covered in the first 20 seconds is $S_2$ then :

Question

( A ) $S_2=3S_1$
( B ) $S_2=S_1$
( C ) $S_2=2S_1$
( D ) $S_2=4S_1$