After recovering from a stroke, Farina was able to learn how to hit a tennis ball. She is unable, however, to learn and remember the name of the rehabilitation therapist who has been working with her each day to develop her tennis swing. Farina is most likely to have suffered damage to her:

Hippocampus

Explanation:

Based on the scenario being described within the question it can be said that the most likely reason for this is that Farina suffered damage to her Hippocampus. This is a complex section of the human brain structure which is located deep within the temporal lobe and who's main function is learning and memory. Which damage to this part of the brain would affect both learning and memory such as it did to Farina.

igneous rocks which formed by the crystallization of magma at the surface of the earth called extrusive rocks. they are characterized by fine-grained textures because the rapid cooling at or near the surface did not provide enough time for large crystals to grow.