A.I. Explanation:

Correct answer: based

Explanation: The word 'based' is the correct choice as it functions as a past participle in the passive voice, indicating the location of the startup, which is essential for understanding the context of the sentence. It aligns with the grammatical structure that requires a past participle to describe the startup's establishment in Palo Alto.

Meaning: 'Based' means to have a main office or center of operations in a specific location.

Wrong options:

• retired: 'Retired' is an adjective that describes someone who has stopped working, which does not fit the context of a startup's location.
• rotated: 'Rotated' is a verb that implies turning or changing position, which is irrelevant in this context.
• during: 'During' is a preposition that indicates a time period, but it does not describe the startup's location.
• dropped: 'Dropped' is a verb that refers to leaving or discontinuing something, which does not relate to the location of the startup.

Correct answer: dropped

Explanation: The term 'dropped' is the correct answer as it is the past tense of the verb 'drop,' indicating that Elizabeth Holmes left college. This fits grammatically and contextually, as it describes an action she took to pursue her entrepreneurial goals.

Meaning: 'Dropped' means to leave or discontinue something, in this case, her college education.

Wrong options:

• retired: 'Retired' is an adjective that does not fit as it does not describe an action taken by Elizabeth.
• based: 'Based' is a past participle that does not convey the action of leaving college.
• rotated: 'Rotated' is a verb that implies turning or changing position, which is not relevant to leaving college.
• during: 'During' is a preposition that indicates a time period, which does not describe an action taken.

Correct answer: through

Explanation: The word 'through' is the correct choice as it indicates the means by which Elizabeth aims to revolutionize health testing. It fits grammatically and contextually, as it connects her vision with the method of achieving it.

Meaning: 'Through' means by means of or via, indicating the method of achieving something.

Wrong options:

• retired: 'Retired' is an adjective that does not fit as it does not relate to the method of revolutionizing health testing.
• based: 'Based' is a past participle that does not convey the means of achieving her vision.
• rotated: 'Rotated' is a verb that implies turning or changing position, which is irrelevant in this context.
• during: 'During' is a preposition that indicates a time period, which does not describe the means of revolutionizing health testing.