Don't get involved with what you think must also be true, or must also have happened, unless you've been asked to do that. Read all the options. Read every sentence in the stimulus material. It's true you're sometimes given irrelevant material, but don't dismiss it until you've actually assessed it in terms of what you've been asked. But one, and only one, of the options is correct in terms of the question.
Ambiguities are deliberate, but a solution has been provided.
Keep track of time, but don't be possessed by it. Resist pressure by working at the fastest pace that is productive for you. Don't waver about guessing. Decide quickly, once you recognize the possibility. Then do it and forget about it.