Directions: Select the option that best replaces the underlined segment to enhance the sentence's conciseness and correctness. Select option D if no correction is needed.

The coach remarked that the athlete tends to relapse back into his previous training routine whenever he leaves the official sports academy.

The correct option is relapse into his previous training routine.

Detailed Explanation:
1. Understanding Redundancy (Pleonasm): The verb "relapse" is defined as falling or slipping back into a former state, practice, or condition. Because the idea of moving "back" is already built into the core definition of "relapse", pairing it with the word "back" (i.e., "relapse back") creates an unnecessary repetition of meaning.
2. Analyzing the Choices:
• relapse into his previous training routine: This removes the redundant word "back", leaving a clear, concise, and grammatically accurate phrase.
• relapse back again into his previous training routine: This worsens the redundancy by adding both "back" and "again".
• relapse backward into his previous training routine: This also repeats the directional meaning already present in "relapse".
• No improvement required: Incorrect because the original phrase contains redundant wording.

Hence, omitting "back" improves sentence conciseness while maintaining the correct grammatical structure.