This is called a "topic sentence." It's common for paragraphs to have the main idea be the first sentence, because this allows the author to set up the rest of the paragraph and explain things immediately after the topic sentence.
The correct answer for the given question above would be the last option. Since expressionists alter the shape of forms, and they use color as <span>an independent expressive element, the artist that served as an inspiration for early expressionist was Vincent van Gogh. Hope this answer helps.</span>
