instruction: Is the next sentence syntactically and semantically acceptable?

Martha said John sang the aria from La Boheme.

response: acceptable

instruction: Is the next sentence syntactically and semantically acceptable?

I think she is pregnant

response: acceptable

instruction: Is the next sentence syntactically and semantically acceptable?

Jeff must have eaten the deep fried muffin.

response: acceptable

instruction: Is the next sentence syntactically and semantically acceptable?

Did Medea poison Jason?

response:
acceptable