OG详解-OG2 文法 Q16

Choice C is the best answer. The convention being tested is punctuation between a subordinate clause and a main clause. This choice correctly uses a comma to mark the boundary between the subordinate clause (“While…lifelike”) and the main clause (“others look to the past”). 
Choice A is incorrect because it results in an incomplete sentence with no main clause. Choice B is incorrect because it fails to mark the boundary between the subordinate clause (“While…lifelike”) and the main clause (“others…past”). Choice D is incorrect because it results in an incomplete sentence with no main clause.