1

Problem

The teacher’s explain of complex mathematical concepts and his approach to solving the problems was insightful.

2

Clue

The word after "teacher’s" must be a singular noun, since it’s the subject of the sentence and pairs with "was.

3

Hint

Look for the correct noun that matches the role in the sentence (subject of the verb “was”).

4

Sumup

Please summarize Problem, Hint, Clue

Choices

6

Choice-A

Choice A is incorrect. "Explain" is a verb, not a noun. You can’t use a verb directly after a possessive noun ("teacher’s"). It breaks noun agreement.

Wrong No change

7

Choice-B

Choice B is correct. "Explanation" is the correct noun form of "explain." It agrees with the singular verb "was" and fits the sentence meaningfully.

Correct teacher’s explanation

8

Choice-C

Choice C is incorrect. "Explains" is a verb in present tense, not a noun. The sentence needs a noun to act as the subject of the verb “was.”

Wrong teacher’s explains

9

Choice-D

Choice D is incorrect. "Explainable" is an adjective, not a noun. It describes something, but it cannot be the subject of the sentence. It causes noun agreement error.

Wrong teacher’s explainable

10

Step

Correct Answer - The teacher’s explanation of complex mathematical concepts and his approach to solving the problems was insightful.

11

Answer

Option

B

12

Sumup

Please summarize choices