A biologist analyzes the dna sequences in three different primates. The biologist finds that primates "a" and "b" have almost exactly the same DNA sequences. the DNA sequences in primate "c" are significantly different from those of primate "a" and primate "b". This information allows the biologist to infer that:
1. primates a and b are more closely related to each other than either is to primate c
2. all 3 primates appeared on earth at about the same time
3. either primate a or primate b must be a direct ancestor of primate c
4. primate c must have been the ancestor of both primate a and primate b.