Respuesta :
Answer:
The correct answer would be option C.
Ribosomal RNA (rRNA) is used as molecular clock due to many factors such as:
It has very slow mutation rate (around 1 million years) due to which it remains highly conserved in all the organisms. The degree of mutations present in rRNAs of two organisms can be directly linked to the time they were evolved in past.
In addition, it has essential biological function due to which it can be found in almost all the organisms.