Step 1: Read the sentence with the underlined parts
(a) had been dead
(b) for five days
(c) The corpse
Step 2: Understand the grammar rule involved
The error here relates to how we express the state of being dead. The verb phrase "had been dead" already indicates a completed condition. It cannot logically be modified by a duration phrase like "for five days," because once someone is dead, it is not a continuous state measured in time the same way "living" or "waiting" can be.
Step 3: Analyze each part
- (a) "had been dead" → Grammatically fine. It is a past perfect construction correctly used to show a completed state before another past event.
- (b) "for five days" → This is the erroneous part. The phrase "for + duration" is used with continuous or ongoing states (e.g., "had been waiting for five days," "had been ill for five days"). But "dead" is an absolute state, not a process that extends over time in grammar usage. Instead, the correct phrasing would be "The corpse had been lying there for five days" or "The person had been dead since Monday." Using "for five days" with "dead" directly is awkward and ungrammatical.
- (c) "The corpse" → This is correct. It serves as the subject of the sentence.
Step 4: Correction of the sentence
Correct form: "The corpse had been lying there for five days"
OR "He had been dead since Monday."
Step 5: Final justification
Thus, the error lies in segment (b) "for five days," because it incorrectly modifies "had been dead."
Final Answer: The correct option is (B) for five days.