I believe it is the final sentence: I left for college when I was 18 (that was also the age at which I was married). This is because the parentheses also give information about another incident that took place at the time - his/her marriage.
The answer is C. Suspenseful and terrified. Why? because the writer is explaining it in a scary way of how she grabbed him by the shirt and shook him so hard that his teeth could have fallen out.
Answer: D
Explanation: the last one sounds the most confident
giving punnishments, bring this theme more public so people are aware of it, show really bad side of this theme so people would understand that its a big problem.