he was in a brown study and did not seem to catch my point.

Let's understand the phrase “in a brown study”. It is an idiom, which means a phrase whose meaning cannot always be understood from its individual words.

The idiom “in a brown study” means being deep in thought, lost in one's own thoughts, or absent-minded, often to the extent of not paying attention to what is happening around oneself.

In the given sentence, “He was in a brown study and did not seem to catch my point,” the person was so absorbed in his own thoughts that he failed to pay attention to or understand what the speaker was saying.

Option A: In his study room — Incorrect. The idiom refers to a mental state, not a physical room.

Option B: Absorbed in reading — Incorrect. The idiom means being lost in thought and does not specifically refer to reading.

Option C: Absent-minded — Correct. An absent-minded person is preoccupied with their own thoughts and may fail to notice or understand what is happening around them.

Option D: In a state of shock — Incorrect. The idiom refers to deep thought or contemplation, not shock or sudden surprise.

Therefore, the correct answer is Option C: Absent-minded.