Statement–Assumption (“Look at her audacity—Madhu has not replied to my letter”): Statement: “Look at her audacity—Madhu has not replied to my letter,” says A to B. Assumptions: I) Madhu received A’s letter. II) Madhu did not receive A’s letter. III) The letter was sent by post.

Introduction / Context:
When someone labels non-response as “audacity,” they attribute deliberate disregard. This framing presupposes receipt of the message.

Given Data / Assumptions:

• Speaker A complains that Madhu has not replied.
• Complaint implies expectation of a response.
• Mode of sending is not specified.

Concept / Approach:
An assumption is necessary if, without it, the speaker’s stance loses force. If Madhu never received the letter, calling her audacious would be unjustified.

Step-by-Step Solution:
I: Receipt of the letter must be presumed to judge the non-reply as audacious; otherwise, there is no intentional slight. So I is implicit.II: Directly contradicts I and the sentiment expressed. Not implicit.III: Delivery channel (“by post”) is not entailed; the letter could have been delivered by hand/e-mail/courier. Not implicit.

Verification / Alternative check:
Everyday conversational logic: attributing blame for non-response typically assumes successful delivery.

Why Other Options Are Wrong:
Including II conflicts with the complaint; including III adds irrelevant detail; “None” ignores the basic premise behind the reproach.

Common Pitfalls:
Assuming specific modes of communication without textual basis.

Final Answer:
Only I is implicit.