Answer: The dictionary definition that best describes how the word "radiant" is used in this sentence is c) filled with light or very bright.
Explanation: The word "radiant" is an adjective and it is generally used to describe something or someone as shining or glowing brightly. In the sentence provided, "radiant" has been used to describe the glow of the silver moon; therefore, it is depicting this glow as something filled with light or very bright. In that way, option c) is the one that provides the meaning of the word "radiant" in this sentence.
