A.I. Explanation:

First sentence: Why this is the first line? This paragraph is the first sentence because it introduces the main topic. It tells us about Hudson leaving England, which starts the story. It does not need any other sentence to understand it. This follows the rule of Topic Sentence. Why other lines are not chosen? The other paragraphs are not chosen because they do not stand alone. For example, Paragraph 2 starts with 'He', which is a pronoun. This means it needs more context to understand. Paragraph 3 starts with 'After', which is a conjunction. This shows it is not independent. Paragraph 4 uses 'The exploration', which assumes we know what exploration it is about. So, these do not meet the rules for being the first sentence.

Concluding sentence: Why this is the last line? This paragraph is the last sentence because it wraps up the story. It shows the final destination of the exploration. This follows the Conclusive Words rule.

Paragraph pairs:

• Pair 1 (Paragraph 1 → Paragraph 2): Paragraph 2 connects with Paragraph 1 because it continues the story. It shows what happened after Hudson left England. This follows the Logical Order rule.
• Pair 2 (Paragraph 2 → Paragraph 3): Paragraph 3 connects with Paragraph 2 because it tells what happened next. After they crossed the ocean, they reached Greenland. This follows the Chronological Order rule.
• Pair 3 (Paragraph 3 → Paragraph 4): Paragraph 4 connects with Paragraph 3 because it shows the next step in the journey. After entering the Hudson Strait, they reached Hudson Bay. This follows the Logical Order rule.