Answer:
most beautiful
Step-by-step explanation:
The superlative form of the adjective 'beautiful' is 'most beautiful,' not 'beautifullest.Words of more than two syllables form the comparative with more and most: beautiful, more beautiful, most beautiful.Adjectives with more than two syllables can only make their comparative by using 'more' and their superlative by using 'most'. beautiful → more beautiful / most beautiful.