Asingle lunar cycle lasts a 1.day2.week3.month4.year

The answer is; 3

A lunar cycle is the phases of the moon as it orbits, once, around the earth (which takes approximately 29.5 days). These phases can be viewed from the earth - new moon to full moon. The light from the sun that hits the moon reflects to the earth. Depending on the position of the moon,  in its orbit, and with respect to a person at a particular position of the earth, the moon will be in a particular phase.  

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.