Scientists review the work of other scientists to ensure the results are in agreement with accepted scientific beliefs
guarantee federal funding by supporting each other's work
keep the science community better informed
validate the results and check the evidence's reliability

it's d - life cycles - apex

i think its both a and b

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.