Final answer:
In the sentence 'I ____ to your e-mail as soon as I get into the office', the correct answer is 'will respond' because the action has not yet taken place but will in the future.
Step-by-step explanation:
The correct answer to the question "I ____ to your e-mail message as soon as I get into the office." is option a) will respond. In this sentence, the speaker is discussing an action that has not yet happened, but will occur in the future, once they arrive at the office. Therefore, the future tense verb phrase 'will respond' is appropriate. The other options, 'am responding', 'have responded', and 'responded' all refer to present or past actions, which do not fit the context of the sentence.
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