Correct Answer: Cloud seeding involves use of chemicals that target rain-bearing clouds above a catchment area such as a river, reservoir or a lake.

Solution : The second option is correct.

Explanation: The indefinite article (a) is used before consonant sounds, and (an) is used before vowel sounds. In this case, the catchment area begins with a consonant sound, so the correct article is a . Additionally, the same principle applies to the subsequent nouns river , reservoir , and lake . Each of these nouns begins with a consonant sound, so a is the correct choice.

Therefore, the sentence that uses the article correctly is: Cloud seeding involves the use of chemicals that target rain-bearing clouds above a catchment area such as a river, reservoir, or lake .