Identify the part of the sentence that contains an error in "Sarah's father, died of heart attack at a very young age."

Introduction / Context:
This error spotting question asks you to analyse a sentence about Sarah's father dying at a young age. The test checks whether you can identify incorrect or missing articles and other small but important grammar features. Mastery of such details is essential for scoring well in English usage sections of competitive examinations.

Given Data / Assumptions:
The sentence is divided into parts:

• (A) Sarah's father, died
• (B) of heart attack at
• (C) a very young age.
• (D) No error

Your task is to choose the part containing the error. Punctuation (the comma) is not usually the focus in such questions; article use is more commonly tested.

Concept / Approach:
The key grammar rule here is that singular countable nouns like "heart attack" require an article when they are used in a general statement. Standard English expressions are "die of a heart attack" or "die of a heart disease". Without the article "a", the phrase sounds incomplete and non standard.

Step-by-Step Solution:
Step 1: Look at part A: "Sarah's father, died". The comma is not ideal, but exam questions in this format generally focus on more obvious grammatical errors rather than minor punctuation. The phrase "Sarah's father died" is otherwise acceptable. Step 2: Examine part B: "of heart attack at". The expression "of heart attack" is missing the article "a". The natural phrase is "of a heart attack". Step 3: Check part C: "a very young age." This is grammatically correct; "at a very young age" is a standard phrase. Step 4: Conclusion: the clearest grammatical error that examiners want is in part B.

Verification / Alternative check:
Read the corrected full sentence: "Sarah's father died of a heart attack at a very young age." This sounds completely natural and follows standard English usage. If we only removed the comma but kept "of heart attack", the sentence would still feel off. This confirms that the missing article in part B is the primary tested error.

Why Other Options Are Wrong:

• Option A: While the comma after "father" is stylistically unnecessary, such punctuation issues are rarely the target in this type of question.
• Option C: "At a very young age" is standard and correct.
• Option D: Cannot be chosen because we have identified a specific grammatical mistake in part B.

Common Pitfalls:
Candidates often overlook article usage in prepositional phrases following verbs like "died of", "suffered from", or "recovered from". Another pitfall is to treat punctuation as the main error even when a more fundamental grammar issue is present. In exam conditions, always prioritise clear grammatical rules about articles, tenses, and prepositions before focusing on commas and stylistic punctuation.

Final Answer:
The error is in part B, because the phrase should read "died of a heart attack at a very young age".