Final answer:
The correct answer is 'is looking' which shows the action of searching for the car keys is happening currently.
Step-by-step explanation:
Ms. Harris is looking for her car keys. The words that show the action is happening now are a.) looks/is looking. When we describe an action that is currently in progress, we often use the present continuous tense, which is formed with the present tense of the verb 'to be' followed by the -ing form of the main verb. In this case, 'is looking' is the correct form to indicate that Ms. Harris is in the process of searching for her car keys at this moment.