This question is incomplete because the controlling idea is missing; here is the complete question:
Read a student's reaction to a nonfiction article.
Summary:
I read an article by Alfred Jenson about oil spills. Jenson has crossed the Arctic Ocean many times on vessels designed for exploration and research. He believes oil spills can be prevented with stricter international regulations governing oil transport.
Controlling Idea:
The controlling idea of Jenson's article is that many oil spills have occurred in recent years in the Arctic Ocean.
What must the student add to make this controlling idea complete?
A. Jenson’s viewpoint
B. Expert testimony
C. Arctic Ocean statistics
D. Specific dates
The answer to this question is A. Jenson's viewpoint
Step-by-step explanation:
The purpose of a controlling idea is to state the position of the author about a topic, which is used to write a text or prepare a speech. Also, it is common the controlling idea mentions first the topic or issue that is going to be discussed, and then the point of view or position of the author about it. This means, in this case, the controlling idea should not only mention the fact Jenson observed many oil spills occurred in the Arctic Ocean but should also state what is the viewpoint or position of the author about this situation.