Which was the first genetic material in living organisms?

The term '$RNA$ world' was coined due to which research finding in the $1980s$ regarding evolution?

Given below are two statements:
Statement $I$: Catalytic RNAs are called ribozymes.
Statement $II$: $RNA$ can undergo mutations,replicate,and catalyse reactions.
In the light of the above statements,select the correct option given below:

The discovery of which of the following in $1980$ led to the term '$RNA$ World' for evolution?

Select an incorrect statement regarding $\text{RNA}$ molecules.

In some viruses,$RNA$ is present instead of $DNA$ indicating that