Since the word is 6 letters with 'a' as the second letter, 'n' is a strong choice. It's one of the most common consonants in English that I haven't guessed yet, and appears in several possible words matching this pattern such as "canvas", "handle", "dance", and "cannot". Given my limited remaining guesses, choosing a high-frequency letter like 'n' gives me the best chance of hitting a letter in the word.