After attending the workshop(A)/ on digital marketing, she learn (B)/valuable strategies to (C)/enhance her online business (D).

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, then choose option ‘No error’ as the answer response. (Ignore errors of punctuation, if any).

The correct answer is B.

Explanation:
Let us analyze the sentence step-by-step to check for grammatical accuracy:

1. Part (A): "After attending the workshop"
This is a past-prepositional clause indicating an action that has already taken place in the past ("attending the workshop").

2. Part (B): "on digital marketing, she learn"
Notice the verb "learn". Since the main action occurred after attending the workshop (past context), the main verb should be in the simple past tense ("learned" or "learnt"). Furthermore, with a third-person singular subject like "she", the present tense form would be "learns", making "she learn" grammatically incorrect in any context.

3. Part (C) & (D): "valuable strategies to" / "enhance her online business"
These parts properly use an infinitive phrase ("to enhance") to state the purpose of the strategies learned, which is grammatically sound.

Correction:
Replace "she learn" in part (B) with "she learned" (or "she learnt").
Correct Sentence: "After attending the workshop on digital marketing, she learned valuable strategies to enhance her online business."

Therefore, the grammatical error lies in part B.