Answer:
d. Coalesce
Step-by-step explanation:
To coalesce means to come together and to form a bigger group or to form a coalition. Here, in the given example, people have become fed up of the government and their lack of action regarding climate change and have therefore come together and has formed a group to organize protests or to take some organized action. Hence, the correct answer is that the people has coalesced to take some organized action in regards to climate change.