The half-life of a first-order reaction is 10 minutes. In what time, the rate of reaction will decrease from 6.0×10²¹ molecules mL⁻¹ s⁻¹ to 4.5×10²⁵ molecules litre⁻¹ min⁻¹ ? (NA​=6.0×10²³)
A.10 min
B.20 min
C.30 min
D.40 min