The correct option is C had been wearing
Answer: Option C, had been wearing, is correct.
Explanation: This is an example of Past Perfect Continuous Tense. It indicates a continuous action (wearing shoes) that was completed at some point in the past. The usage is the verb (wear) with an -ing at the end.
Option A is incorrect: the subject (he) is singular, hence were (plural) can't be used.
Option B is incorrect because are indicates present (and is plural too)
Option D: was wearing indicates he's still wearing the shoes. Hence, it is incorrect
Option E: had been worn is grammatically incorrect