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 risotto. It sets up the idea of selecting the right rice, which is important for the dish. This follows the rule of Topic Sentence. Why other lines are not chosen? The other paragraphs do not qualify as the first sentence because they either refer to actions that come after selecting the rice or use words that need prior context. For example, Paragraph 2 starts with 'The first step,' which needs a previous sentence to understand what the first step is. Paragraph 3 talks about adding rice, which also needs the context of selecting it first. Paragraph 4 mentions sautéing onions, which is another step that comes after choosing rice. Paragraph 5 talks about stirring, which is a later action.

Concluding sentence: Why this is the last line? This paragraph is the last sentence because it wraps up the cooking process. It explains the final important action needed to finish the risotto, which is stirring. This follows the rule of Conclusive Words, as it gives a final detail about the dish.

Paragraph pairs:

• Pair 1 (Paragraph 1 → Paragraph 2): Paragraph 2 connects with Paragraph 1 because it continues the process of making risotto. The phrase 'The first step' shows a logical order of steps in cooking.
• Pair 2 (Paragraph 2 → Paragraph 3): Paragraph 3 follows Paragraph 2 because it describes what to do after sautéing onions. The action of adding rice comes next in the cooking process, showing a logical order.
• Pair 3 (Paragraph 3 → Paragraph 4): Paragraph 4 connects with Paragraph 3 because it explains what to do after toasting the rice. The phrase 'To achieve perfection' shows the next step in the cooking process.
• Pair 4 (Paragraph 4 → Paragraph 5): Paragraph 5 follows Paragraph 4 because it talks about stirring the risotto after adding broth. This shows a cause and effect relationship, where stirring helps achieve the creamy texture.