Find out whether there is any grammatical error in below sentence. I had hoped to have met him yesterday / to discuss the matter with him / but he was not in his house, and so I could not meet him.

The correct answer is D. No error.

The sentence is grammatically correct. The use of the past perfect tense “had hoped” indicates that the action of hoping took place before another action in the past, which is “met him yesterday.” The use of the infinitive “to discuss the matter with him” indicates that the speaker had an intention to discuss the matter with the person they were hoping to meet. The use of the past participle “not in his house” indicates that the person they were hoping to meet was not at home. The use of the conjunction “but” indicates that the speaker’s hope was not fulfilled, and the use of the past modal “could not” indicates that the speaker was unable to meet the person they were hoping to meet.