When separating items in a list, a writer should 1)end the list with a colon. 2)separate the items with colons. 3)add a comma after the “and” before the last item. 4)add a comma before the “and” before the last item.

D

add a comma before the “and” before the last item.

Explanation:

the correct way to cite this in apa format is the following: smith, d. (2001). world environment day. retrieved from  

apa (american psychological association) style is most commonly used to cite sources within the social sciences.  

quotation styles can differ by use and by styles and every subject has its own unique style of quotation.

explanation: