Which sentence contains a list that is punctuated correctly?

a. my favorite foods include chicken tamales, beef fajitas and black beans.
b. one day, i hope to own a blue car, a purple motorcycle, and a yellow truck.
c. the farm we visited grew vegetables; fresh herbs; and flowers.
d. for the camping trip, we packed a water bottle a nylon tent, and a fishing pole.

A is the correct answer because when listing items of three or more a comma is necessary to break up the listed items. However, the second to last item before the and may or may not need a comma. If a comma is included (in this case after beef fajitas and before and) the sentence is still correct; this is referred to as an oxford comma. This answer does not include the oxford comma, and is still grammatically correct.