I believe it’s B, I’d choose B if I were you.
The answer would be C., Suversive activity.
Subversive activity refers to all willful acts that have the intention of being detrimental to governmental interests that don't really fall into the specific categories of; treason, sedition, sabotage... etc
The correct answer is - remained a political movement.
The Solidarity labor union continued its existence and remained a thorn in the eyes of the leading political parties, by constant monitoring of the situation in the market and labor, they very often made protests and occasionally riots, especially where the prices of the most important products were going up.
