The rate of a first order reaction is $0.04 \; mol\; l^{-1} s^{-1}$ at 10 seconds and $0.03 \; mol\; l^{-1}\; s^{-1}$ at 20 seconds after initiation of the reaction. The half-life period of the reaction is :

Question

( A ) 34.1 s
( B ) 44.1 s
( C ) 54.1 s
( D ) 24.1 s