In the following sentence, some part of the sentence may have an error. Identify the part that contains an error, or select "No error" if the sentence is grammatically correct. Sentence: In spite of her irritation, she could not help smile.

Introduction / Context:
This error spotting question focuses on verb patterns after certain fixed expressions. The sentence is split into parts A, B, C and D. You need to find which part contains a grammatical error related to the form of the verb after the expression "could not help".

Given Data / Assumptions:

• Part A: In spite of
• Part B: her irritation, she
• Part C: could not help smile.
• Part D: No error.
• The full sentence is "In spite of her irritation, she could not help smile."

Concept / Approach:
The expression "cannot help" or "could not help" is normally followed by a gerund form of the verb, that is, the ing form. For example, "She could not help laughing" or "He cannot help smiling". When "help" is used in this idiomatic way, the base form of the next verb is not standard in formal English. Therefore, "could not help smile" is incorrect, and it should be "could not help smiling".

Step-by-Step Solution:
Step 1: Check part A, "In spite of". This is a correct prepositional phrase used to show contrast.Step 2: Check part B, "her irritation, she". This correctly introduces the subject "she" and the phrase "her irritation". No error here.Step 3: Check part C, "could not help smile". Here, the structure "could not help" is followed directly by the base verb "smile". The standard pattern requires a gerund, so it should be "could not help smiling".Step 4: Because part C contains the incorrect verb form, this is the segment with the error.Step 5: The corrected full sentence becomes: "In spite of her irritation, she could not help smiling."

Verification / Alternative check:
Compare with similar examples. We say "He could not help laughing at the joke" and "They could not help admiring her courage". In both cases, the ing form follows "could not help". If you replace those with "could not help laugh" or "could not help admire", the sentences sound unnatural and would be considered incorrect in examinations. This pattern confirms that "could not help smiling" is the right form.

Why Other Options Are Wrong:
There is nothing wrong with parts A and B, which correctly set up the contrast and introduce the subject and her emotional state. Part D, "No error", is wrong because we have clearly identified an error in part C. Therefore only C can be selected.

Common Pitfalls:
Learners sometimes confuse different uses of "help". When "help" means "assist", it can take an object and possibly a bare infinitive, as in "She helped him finish the work". But in the fixed expression "cannot help doing something", "help" means "cannot avoid" and is always followed by a gerund. Remembering this distinction is essential for error spotting questions like this one.

Final Answer:
The error is in part C, where "could not help smile" should be corrected to "could not help smiling".