Answer: D) Ani is the better gymnast of the two.
Step-by-step explanation: An adjective is a word that modifies a noun, by giving it some attributes. A comparative adjective is used when comparing characteristics between two subjects (people, animals, objects, etc). From the given sentences, the first one has a superlative adjective (best), the second one makes a comparison but using and adverb (more), the third one doesn't make any comparison, and finally, the last one is the correct answer because it uses the comparative adjective "better."