In this Direct and Indirect Speech question, pick the correct Indirect Speech form of the statement: "Heena said, 'I bought a dress yesterday.'"

Introduction / Context:
This question examines how to report a simple past statement with a time expression from Direct Speech into Indirect Speech. The sentence is: Heena said, "I bought a dress yesterday." To answer correctly, you must know how to backshift the tense from simple past to past perfect and how to change the time word yesterday in reported speech.

Given Data / Assumptions:

- Direct speech: I bought a dress yesterday. - Reporting clause: Heena said. - Reporting verb: said, in the past tense. - Time expression: yesterday, referring to the day before the day of speaking.

Concept / Approach:
When the reporting verb is in the past tense, the simple past in the reported clause often changes to past perfect in indirect speech to emphasize that the action took place before the reporting moment. So bought becomes had bought. The pronoun I refers to Heena and must change to she. Time expressions such as yesterday usually become the day before or the previous day to maintain clarity when viewed from a later time. The conjunction that is commonly used after said in reported speech.

Step-by-Step Solution:

Verification / Alternative check:
To verify, convert this indirect sentence back to direct speech. From Heena said that she had bought a dress the day before, you change she had bought back to I bought and the day before back to yesterday. Reinsert quotation marks: Heena said, "I bought a dress yesterday." As this matches the original statement, the indirect speech form is confirmed as correct.

Why Other Options Are Wrong:
Option A uses has bought, which is present perfect, instead of had bought. Option C and option D mix the expression day before yesterday with has bought or had bought, adding an extra day and changing the time reference. Option E is close in meaning and grammatically acceptable in many contexts, but the standard textbook transformation used in competitive exams is the day before rather than the previous day in this specific situation. Option B matches the conventional rule exactly, using had bought with the day before, so it is the preferred answer.

Common Pitfalls:
A common mistake is to leave the verb in simple past when a more precise past perfect form is expected in formal reported speech. Students also sometimes forget to change I to she or to adjust time expressions like yesterday, today and tomorrow. Confusion between the day before and the day before yesterday is frequent, but they do not mean the same thing. Always track when the action happened relative to the reporting and choose the appropriate indirect time expression accordingly.

Final Answer:
The correct reported speech sentence is Heena said that she had bought a dress the day before.