Final answer:
The test described relies on recognition retrieval, where Sharon identifies words she previously learned after encountering them again.
Step-by-step explanation:
The test described, where Sharon is shown a list of 30 words and then asked to circle the words she remembers, relies on recognition retrieval. Recognition occurs when you identify information that you have previously learned after encountering it again. In this test, Sharon is comparing the words on the new list to the original list to determine which ones she remembers.