Final answer:
The best choice for maintaining consistency in the given sentence is option 2, 'You,' which aligns with the second-person pronoun used at the beginning of the sentence.
Step-by-step explanation:
The question presents a sentence with a mismatch in pronoun consistency, which is a common issue in maintaining a formal and coherent writing style. In the given sentence, 'You should always be on the lookout for new opportunities, but one should also avoid burning bridges if possible,' the pronouns 'you' and 'one' should match to maintain consistency.
Thus, the corrected version should use the same pronoun throughout the sentence. The most appropriate choice would be 'You should always be on the lookout for new opportunities, but you should also avoid burning bridges if possible,' matching the second-person point of view established at the beginning of the sentence.