Which of the following $RNA$ is non-functional?

Which of the following is not a type of $RNA$?

The most abundant $RNA$ found in a cell is .......

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:

Given below are two statements:
Statement $I$: $RNA$ mutates at a faster rate.
Statement $II$: Viruses having $RNA$ genome and shorter life span mutate and evolve faster.
In the light of the above statements,choose the correct answer from the options given below:

The $A/U$ and $G/C$ ratio in $RNA$ is: