A.I. Explanation:

First sentence: Why this is the first line? This paragraph is the first sentence because it introduces the main topic. It gives a clear statement about the Ottonian dynasty. This follows the rule of Topic Sentence. It does not need any other sentence for context. Why other lines are not chosen? The other paragraphs are not chosen because they do not stand alone. For example, Paragraph 2 starts with 'It', which is a pronoun. This means it needs more information to understand. Paragraph 3 also starts with 'It', so it is not independent. Paragraph 4 starts with 'The', which needs prior knowledge about the family. Therefore, they do not qualify as the first sentence.

Concluding sentence: Why this is the last line? This paragraph is the last sentence because it wraps up the information about the family. It gives a final detail about the name Liudolfings. This follows the rule of Summary Style, as it brings together the earlier points about the dynasty.

Paragraph pairs:

• Pair 1 (Paragraph 1 → Paragraph 2): Paragraph 2 connects with Paragraph 1 because it explains more about the Ottonian dynasty. It uses the Connector strategy. The phrase 'It was named after' shows that it continues the idea from the first paragraph.
• Pair 2 (Paragraph 2 → Paragraph 3): Paragraph 3 connects with Paragraph 2 because it gives more information about the name of the dynasty. It uses the Broader to Specific Strategy. The second paragraph talks about the name, and the third paragraph explains another name it is known by.
• Pair 3 (Paragraph 3 → Paragraph 4): Paragraph 4 connects with Paragraph 3 because it continues to talk about the family. It uses the Logical Order strategy. The third paragraph mentions the Saxon dynasty, and the fourth paragraph gives another name for the family.