Answer:
C. A swelling movement sweeping others in a shared direction
Explanation:
This can be understood in two ways. One, by understanding the statement within its context and then trying to understand what the word could mean; and second, with the help of substituting the meaning of the word, adjusted in the original sentence, and relating it with the context to see if it makes sense.
Understanding the Context
The sentence talks about a popular opinion being effectively changed. which remained as it was for a long time, since the change was 'long overdue.' Clearly it requires a massive force to move or even budge a long established and popular opinion, and that massive force can be compared to the force that a wave (literal meaning implied) can exert, sweeping away all that comes before it, in its own direction. Option C matches this description of the wave, and hence is the correct answer.
Substituting the Meaning
"Both effectively changed the popular opinion about emotional issues for their countries and brought in a swelling movement sweeping others in a shared direction of change that was long overdue."
Here, we can observe that the meaning remains the same and makes sense, and hence C is the correct option.
