Respuesta :
C. At the urging of many, government leaders looks for ways to reduce pollution.
Answer:
B. Scientists studied the trapping of glass in the atmosphere.
Explanation:
A gerund phrase is a phrase that starts with a verb using -ing form and that is functioning as a noun, when the gerund phrase is been used as the direct object of the sentence, the gerund phrase is the receiving object of the verb perfomed by the subject in the sentece, now form our options only B and C have gerund phrases, but only on B "Scientists studied the trapping of glass in the atmosphere.", the gerund phrase "Trapping of glass" is been used as a direct object since it is the noun that is receiving the verb, since Trapping glass is the things scientists are studying.