I'm choosing 't' because it's one of the most common consonants in English. It frequently appears before vowels, after vowels, and at the end of words. Given our pattern '_a_e__', 't' could potentially fit in multiple positions, including before 'a', between 'a' and 'e', or in the final positions. Words like "table", "dates", "later", etc. all contain 't' in useful positions.