Given below are two statements. One is labelled Assertion (A) and the other is labelled Reason (R).
Assertion (A): Viruses have shorter life span, mutate and evolve faster.
Reason (R): This is because most of the virus have RNA as genetic material.
In light of the above statements, choose the correct answer from the options given below.
 

The assertion is true. Viruses tend to have shorter generation times and life spans compared to larger organisms. This means that they can go through many replication cycles in a short period, increasing the chances of mutations occurring in their genomes during replication. These mutations can contribute to the virus's ability to adapt and evolve quickly in response to changing environmental conditions and host defenses. 
The reason is also true.  Many viruses have RNA genomes (RNA viruses), and RNA viruses are known to have higher mutation rates compared to DNA viruses. This is not the sole reason for the faster mutation and evolution of viruses. Viruses, having shorter life spans, mutate and evolve faster because viruses mostly have an RNA genome. 
Both assertion and reason are correct, and reason explains assertion.