The choice which is an example of a comparative form is option A. Better.
Better is the comparative form of the verb "good" and its superlative form is "best."
Adjectives tend to change in spelling according to how they are employed in a sentence. Adjectives have three forms: positive, comparative, and superlative. The simplest form of the adjective is its positive form. In order to compare two objects or persons, the comparative form of the adjective is used.
