Option A is the right answer.
Repetition is the act of repeating something that has previously been stated or recorded. Though we can repeat some words in the formation of a sentence, it creates a sentence very unattractive. Therefore, by changing some words, or by changing some form of the sentence we can avoid repetition. As in the given statement, the repetition of words can be replaced by option A. Avoiding repetition with some other words does not change the meaning of the sentence of the statement.