A.I. Explanation:

First sentence: Why this is the first line? This paragraph is the first sentence because it introduces the main topic of the text, which is the need for a home exercise routine. It sets the stage for the discussion without needing prior context. It uses a broad overview to explain the importance of exercise in today's world. Why other lines are not chosen? Paragraph 2 starts with "A common starting point" which is not general enough to stand alone. Paragraph 3 starts with "Those new to fitness" which refers to a specific group and needs context. Paragraph 4 starts with "Following a structured schedule" which also requires prior information to understand.

Concluding sentence: Why this is the last line? This paragraph is the last sentence because it wraps up the discussion by emphasizing an important point about fitness. It summarizes the need for rest days, which is a key part of a fitness routine.

Paragraph pairs:

• Pair 1 (Paragraph 1 → Paragraph 2): Paragraph 2 connects to Paragraph 1 because it gives a specific way to achieve the general idea of establishing a home exercise routine. This follows the Broader to Specific Strategy.
• Pair 2 (Paragraph 2 → Paragraph 3): Paragraph 3 logically follows Paragraph 2 because it discusses how to stay motivated after identifying exercises. This shows a Logical Order of ideas.
• Pair 3 (Paragraph 3 → Paragraph 4): Paragraph 4 connects to Paragraph 3 because it highlights an important aspect of fitness that supports the goals mentioned in Paragraph 3. This follows the Cause and Effect Relationship.