Select the most appropriate option to fill in the blank.

If I ______ a doctor, I would have treated you all.

were

The correct option to fill in the blank is were.

The sentence is about a hypothetical situation in which the speaker is a doctor. The word "were" is the past subjunctive form of the verb "to be". It is used to express a hypothetical situation that is not real or possible. In this case, the speaker is not a doctor, but they are imagining what they would do if they were a doctor.

The other options are not as appropriate.

• Would is the modal verb of possibility. It is used to express something that is possible or likely to happen. However, in this case, the speaker is not talking about something that is possible or likely to happen, they are talking about a hypothetical situation.
• Am is the present tense form of the verb "to be". It is used to express something that is true in the present moment. However, in this case, the speaker is not talking about something that is true in the present moment, they are talking about a hypothetical situation.
• Could is the modal verb of ability. It is used to express something that is possible or that someone is capable of doing. However, in this case, the speaker is not talking about something that is possible or that they are capable of doing, they are talking about a hypothetical situation.