Directions: Read the sentence to find out whether there is any grammatical or idiomatic error in it. The error, if any, will be in one part of the sentence. The corresponding letter of that part is the answer. If the given sentence is correct as it is, select 'No error' as the answer response. (Ignore errors of punctuation, if any).

Upon completing the seminar (A)/ on financial planning, he discover (B)/ practical methods to (C)/ expand his consultancy firm (D).

The correct option is B.

Explanation:
Part (B) of the sentence contains a subject-verb agreement error: "on financial planning, he discover".

The pronoun "he" is third-person singular. In the present tense, it requires a singular verb ending in "-s" (discovers), or in the past tense, it requires the past form (discovered). The base form "discover" is grammatically incorrect when paired with "he".

Corrected Sentence:
"Upon completing the seminar on financial planning, he discovers (or discovered) practical methods to expand his consultancy firm."