Answer: <span>B) Because the topic could make the people involved in the discussion tense or angry </span> --------
The word "controversial" means that the topic is likely to cause disagreement among people. In other words, the topic of religion is greatly disagreed upon depending on factors such as interpretation, culture, or geography. It usually sparks angry/tense discussion among people.
The body gives reasons because it is where you give evidence and reasoning. The introduction just introduces a topic while a the thesis does the same. The conclusion ends the writing so the only logical answer is the body.