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 (a). The paragraph should begin with a definition, then give details and benefits in a logical sequence. Sentence 2 is the best opening because it defines food processing and introduces the topic clearly. Sentence 3 naturally follows because it explains what these techniques are. The phrase These techniques directly refers back to the set of techniques mentioned in sentence 2. Sentence 1 then states one major purpose/benefit: safety and freedom from harmful microbes and impurities. This is a logical continuation after describing the techniques. Sentence 4 starts with In addition, which adds extra benefits beyond safety, such as shelf life and nutritional improvement, making it the best concluding line. Cohesion clue: Reference words like These (sentence 3) and connectors like In addition (sentence 4) help confirm the order. So the correct answer is (a)