Yes, A is much too strong. But even if A were weaker, it still wouldn't be supported. This is all based on a distorted reading of the text. Just because two things are said next to each other doesn't mean there's a connection that the text doesn't actually support.
We learn that many artists abandoned Scar Art, yet there was still a focus on rural life, which gave rise to Native Soil. There's no implied connection at all between the increased use of Scar Art for political purposes and the Native Soil movement. It's possible that the Native Soil movement would have began regardless of the weakening of Scar Art. The passage is merely saying that the two happened in the same time period (1980s)--Scar Art weakened and Native Soil rose.
(D) is unsupported. Many details are given about Revolutionary Realism and the Native Soil movement, and yet none of those details are something that both movements share in common.
There is a reason this choice is attractive. Both movements share the quality of idealizing stuff. Whereas the Scar artists emphasized realism and depicting bleak stuff, both Revolutionary Realism and the Native Soil romanticized aspects of "Chinese society." This is all explicitly supported by the text.
Nevertheless, the answer choice says it had several key elements in common--which is not the case. But it's still worth noting there is some serious value to that choice, and this is part of the reason the reading comprehension section can be difficult.
E should stand out as the winner no matter what. While the Scar artists emphasized the damage from modernization, the Native Soil artists idealized the historical peasant life. Both movements were against modernization and the rigidity of the Cultural Revolution, but expressed it in different ways.