The answer you are looking for is letter b. stage a night attack.
The book Great Commanders and Their Battles by Anthony Livesey describes the victories of twenty military minds of history within two thousand years.
This fragment of the book shows that the generals wanted Alexander to stage a night attack.
"Alexander made a reconnaissance in person of the enemy's strength and dispositions and, despite the eagerness of most of his generals, he decided against a night attack. Instead, he retired to his tent to devise his strategy. He ordered his troops to be well fed and then to rest. Darius, on the other hand, mindful of Alexander's unpredictable manoeuvres, ordered his army to stand to throughout the night in readiness for a surprise attack. It is certain that the alertness of one side and the fatigue of the other played at least some part in the outcome of the battle next day."
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