The answer is Are anxious, because it is the correct saying, and fits best in the sentence.
If it's in present tense then A because is wouldn't make sense.
If it's past then D would be correct because was doesn't sound correct English.
The correct option to complete the sentence is A. 'are anxious.' This is because the phrase 'as well as' indicates that the focus is on 'his players,' which is plural, requiring a plural verb.
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