The reaction A $\to$ B follows first order kinetics. The time taken for 0.8 mole of A to produce 0.6 mole of B is 1 hour. What is the time taken for conversion of 0.9 mole of A to produce 0.675 mole of B

Question

( A ) 0.5 hour
( B ) 0.25 hour
( C ) 1 hour
( D ) 2 hour