describe the evolution of homo sapiens from austropith ancestor and clarify the order in which distinctive human traits arose

well, that's easy; the answer's c, "it reduces contamination of the water and substrate of the estuary."

the correct answer is option d.

an appositive is a noun, noun phrase or noun clause which follows another noun or noun phrase in order to describe it or name it another way. they are usually used between commas, brackets or dashes.

the example sentence with the correct use of commas is the following:

her uncle, the man over there in the red shirt, owns the hardware store in town.