Idon't understand this!
nucleotide substitutions occur by mistake in a segment of ribosomal rna at a constant rate of one substitution every 10,000 years. a biologist has compared the ribosomal rna of two modern0day species and found that they have six differences in their sequences. how many years ago did these species diverge from a common ancestor? (2 points)
select one:
a. 3,000 years ago
b. 60,000 years ago
c. 30,000 years ago
d. 6,000 years ago