I'm choosing 's' because it's one of the most common consonants in English that I haven't guessed yet. Looking at the pattern "r__t__", there are several possible words that could fit like "roster", "raster", or the 's' might appear at the end as in "rights". Given that I only have 2 wrong guesses left, I need to choose high-probability letters, and 's' appears frequently in English words.