The original sentence requires the simple present tense in the first part and the simple future tense in the second part. The simple present tense is used in the dependent clause (as soon as he gets his passport) to express a future event that is expected to happen before another future event. The simple future tense is used in the main clause (he will travel to Europe) to express a future action. The correct answer is "As soon as he gets his passport, he will travel to Europe."