The correct answer is C. absent-minded.
A brown study is a state of deep thought or abstraction, often characterized by a lack of awareness of one’s surroundings. Someone who is in a brown study may seem to be daydreaming or not paying attention, and they may not respond immediately to questions or requests.
Option A is incorrect because it is not possible to be in a study room and in a brown study at the same time. A study room is a place where people go to study, while a brown study is a state of deep thought.
Option B is incorrect because it is possible to be absorbed in reading without being in a brown study. Someone who is absorbed in reading may be focused on the book and not paying attention to their surroundings, but they are not necessarily in a state of deep thought.
Option D is incorrect because it is possible to be in a state of shock without being in a brown study. Someone who is in a state of shock may be dazed or confused, and they may not respond immediately to questions or requests, but they are not necessarily in a state of deep thought.