Explanation:
> "He acts ____ he were a general manager."

The sentence is expressing a hypothetical situation, where the person is acting as though they are something they're not. In such cases, we often use the phrase "as if" to introduce a hypothetical or unreal condition.

Now, let's look at the options:

- A. as — "As" is used to compare or describe a function, but it doesn’t work for expressing a hypothetical situation in this context. Incorrect.
- B. if — "If" alone doesn't properly fit the sentence structure here. You need the complete phrase "as if" to express the hypothetical. Incorrect.
- C. as if — This is the correct choice. "As if" is used to express something that is not true but is being acted upon, fitting the context perfectly. Correct.
- D. so as — "So as" is not used in this type of sentence structure. Incorrect.
- E. that — "That" doesn’t fit the context of expressing a hypothetical situation. Incorrect.