Rearrange the following sentences to form a coherent paragraph:

1. This process helps ensure that the food we consume is safe and free from harmful microbes or other impurities.

2. Food processing refers to a set of techniques used to convert raw ingredients into edible products.

3. These techniques may include simple steps like chopping and grinding, as well as advanced procedures such as pasteurization and fermentation.

4. In addition, it supports preservation by increasing shelf life and can also improve nutritional value.

The correct option is 2, 3, 1, 4.

To arrange the given sentences into a logical and coherent paragraph, let us analyze the role and connecting clues of each sentence:

1. Identify the introductory sentence (Sentence 2):
Sentence 2 introduces the primary topic of the paragraph: "Food processing refers to a set of techniques used to convert raw ingredients into edible products." It provides the overarching definition, making it the most suitable opening statement.

2. Connect definitions with examples/details (Sentence 3):
Sentence 3 starts with "These techniques...", directly referencing the "set of techniques" mentioned at the end of Sentence 2. It gives examples of these techniques (chopping, grinding, pasteurization, fermentation). Therefore, Sentence 3 logically follows Sentence 2.

3. Explain the outcome/benefit of these techniques (Sentence 1):
Sentence 1 begins with "This process helps ensure...", which refers to the overall food processing techniques described in Sentences 2 and 3. It explains the main benefit: ensuring that food is safe and free from harmful microbes.

4. Add additional benefits (Sentence 4):
Sentence 4 begins with the transition phrase "In addition...", indicating that it is adding another benefit to the primary one already stated in Sentence 1. It mentions shelf life preservation and nutritional value enhancement.

Putting it all together, the correct sequence is 2 → 3 → 1 → 4.