Hint for process of elimination: Read the sentences with the underlined phrase replaced with each of the multiple choices. Some of them sound very wrong, such as choices A and E. Now that you have eliminated two choices, you must guess on this problem.
Read on for a full solution.
Solution: The pronoun “it” incorrectly refers to plural “computers”. Also, the future tense “will become” and present progressive “replacing” fail parallelism. This version corrects them by putting both verbs in the future tense.