instruction: Is the next sentence syntactically and semantically acceptable?

What Medea arranged was for her children to be poisoned.
OPTIONS:
- unacceptable
- acceptable

response: acceptable

instruction: Is the next sentence syntactically and semantically acceptable?

Everyone had been worrying himself stiff.
OPTIONS:
- unacceptable
- acceptable

response: acceptable

instruction: Is the next sentence syntactically and semantically acceptable?

Who bought what?
OPTIONS:
- unacceptable
- acceptable

response: acceptable

instruction: Is the next sentence syntactically and semantically acceptable?

How do you think that Mary solved the problem?
OPTIONS:
- unacceptable
- acceptable

response:
acceptable