To solve this question, the user needs to know the correct form of the conditional sentence. In this case, it is a type 2 conditional sentence, which expresses an unreal or improbable situation in the present or future. The sentence requires the use of the past tense in the if-clause and the modal auxiliary verb "would" in the main clause.

Now, let's go through each option and explain why it is right or wrong:

A. was: This option is incorrect because "was" is the past tense form of the verb "be" used for the first and third person singular. However, the sentence requires the use of the past tense in the if-clause, which is "were" for all persons.

B. am: This option is incorrect because "am" is the present tense form of the verb "be" used for the first person singular. However, the sentence requires the use of the past tense in the if-clause, which is "were" for all persons.

C. were: This option is correct. "Were" is the past tense form of the verb "be" used for all persons in the if-clause of a type 2 conditional sentence. The sentence requires the use of the modal auxiliary verb "would" in the main clause. Thus, option C is the correct answer.

D. would be: This option is incorrect because "would be" is the conditional form of the verb "be" used in the main clause of a type 1 conditional sentence. However, the sentence requires the use of a type 2 conditional sentence, which requires the modal auxiliary verb "would" in the main clause.

The Answer is: C. were