Read the following paragraph and determine carefully the main idea. From the given four choices, select the one statement that best supports the author's point:

Critical Reading is a demanding process. To read critically, you must slow down reading and, with a pencil in hand, perform specific operations on the text. Mark up the text with your reactions, conclusions and questions. When you read, you become an active participant. 

This paragraph best supports the statement that

Option A is incorrect because the paragraph does not portray critical reading as a dull process. Option B portrays what critical reading is about, but the paragraph does not discuss this; it only talks about how one can go about doing critical reading. Option C is also incorrect because the paragraph does not support critical reading as something that happens at critical times in a person's life. Option D is the correct answer. The paragraph explains that critical reading requires slowing down and making careful choices.