instruction: Is the next sentence syntactically and semantically acceptable?

Ayala sent back her cousin the diamond necklace.

response: unacceptable

instruction: Is the next sentence syntactically and semantically acceptable?

The Shah slept in a bed.

response: acceptable

instruction: Is the next sentence syntactically and semantically acceptable?

A magnificent diamond sparkled on his finger.

response: acceptable

instruction: Is the next sentence syntactically and semantically acceptable?

I believe it to be the switch that is defective.

response:
acceptable