Answer:
D. A list of all green and blue shirts
Step-by-step explanation:
Without the actual query used, it is uncertain how the AND keyword was used, and therefore the results obtained. In the strict sense of the AND meaning you may expect to obtain both green & blue tshirts. For that reason D option fits more appropriate than other choices.
However if not used carefully, a simple WHERE clause like this:
WHERE tshirt.color = "green" AND tshirt.color = "blue"
will return zero results, since the same tshirt.color field cannot be "green" & "blue" at the same time.