Out of the options select the one which best expresses the following…

The correct answer is Option (1) → The daughter told her mother that they had not returned the keys.

Statement in indirect speech:

Change	Direct	Indirect	Why
Reporting verb	said to	told	“Said to” + listener becomes “told” + listener.
Linking word	“ ” (inverted commas)	that	A statement is joined with “that”. The inverted commas go.
Tense change	have not returned	had not returned	With a past reporting verb, the present perfect “have not returned” moves back to the past perfect “had not returned”.
Full sentence	The daughter said to her mother, “They have not returned the keys”.	The daughter told her mother that they had not returned the keys.

Example: He said to me, “I have lost my pen.” → He told me that he had lost his pen.

Why the Other Options are Incorrect?

Option 2: The daughter had told mother that they have not returned the keys. — Incorrect.

• The reporting verb wrongly changes to "had told".
• The reported verb "have not returned" is not moved back.
• "Her" before mother is dropped.

Option 3: The daughter told mother that they are not returning the keys. — Incorrect. The tense changes to the present continuous ("are not returning"), which changes the meaning: the keys have not been returned, not that they are not being returned now.

Option 4: The daughter informed mother that they had not return the keys. — Incorrect. "Had not return" is wrong. The past perfect needs the past participle "returned".