Correct Answer: B
Explanation:
The word, ‘nightmares’ would render a significant meaning to the sentence when placed in the blank but no other word in the given list of answer options means the same as ‘nightmares’ and hence, A is incorrect. Out of the remaining answer options, ‘ruminations’ and ‘cogitations’ are the only two words that carry the same meaning and hence, B and C are the correct answers.