To keep stored food safe, you should:
o a. place the food directly on the floor
ob. label all food with a "use-by” date
oc. store thawing meat on the top shelf
o d. leave all food uncovered

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.