The correct option is D this movement
Let’s examine the portion of passage marked as 7: “Artists associated with [7] this began to rediscover and promote the work of the Mexican muralists, particularly Siqueiros.” The sentence uses the determiner ‘this.’ Both this and that are known as demonstrative determiners, or demonstrative pronouns. Both this and that are used with the singular form of the verb and refer to one object, person, or place. However, the object being referred to by ‘this’ in the sentence is not given in the sentence. We have to incorporate the object after ‘this’ in the sentence. The object is something artists are usually associated with. When we read the rest of the passage, we can infer that it talks about movement and artists are associated with ‘movement.’ Hence, to correct the sentence, we must include ‘movement’ after ‘this.’ So, Option D is the correct answer.