Which of the following statements about thermal cracking is accurate?

Explanation

Option A is incorrect because even moderate temperature changes can influence cracking depth. Option B is wrong since increased residence time typically intensifies cracking severity. Option C is true in that low pressure favors light hydrocarbon production, but it doesn't address the main point here. Option D is correct because deeper cracking breaks molecules into smaller fragments, which lowers the octane number of the resulting gasoline.