The term lead-ins can be defined as an introduction to a subject. It helps to move from one part to other parts of something smoothly.
Long lead-ins <u>are the long introductory words that speak the obvious and can be ignored. The long lead-ins can be removed to make the introduction apt. The writer sometimes uses these long lead-ins to elongate their introduction and appeal to the reader's eye</u>.
<u>But the fact is that these long lead-ins are unnecessary and can be avoided. Deleting long lead-ins makes the text concise and appealing</u>.
The answer is C because she or he is giving reasons like its not reasonable to prepare at the last minute on an exam then you would fail. It also says that if you don't prepare for a marathon you''ll probably get last place like a low grade on a exam.