What is the superlative form of the adjective 'happy"? He is __ A the happiest B the most happy C happilyest D happiestest

The correct answer is **A. the happiest**."Happy" is a one-syllable adjective. The superlative form of one-syllable adjectives is generally formed by adding "-est" (e.g., tall - tallest, big - biggest). While "most happy" is grammatically correct, "happiest" is the more common and concise superlative form. Options C and D are incorrect grammatical formations.