What makes ribosomal RNA useful as a molecular clock?

-A large portion of the DNA ring is not vital to structure or function, allowing it to accumulate neutral mutations.

-Its rate of mutation increases over time as organisms continue to evolve and differentiate from each other.

-A slow mutation rate makes it useful for determining evolutionary relationships between ancient species.

-It is only found in select organisms, making it easier to compare relationships between species that have it.