instruction: Is the next sentence syntactically and semantically acceptable?

I visited every town in every country I had to.

response: unacceptable

instruction: Is the next sentence syntactically and semantically acceptable?

Kelly buttered the bread with unsalted butter.

response: acceptable

instruction: Is the next sentence syntactically and semantically acceptable?

The TA who graded him says that John did really well.

response: acceptable

instruction: Is the next sentence syntactically and semantically acceptable?

Ron failed biology, unfortunately

response:
acceptable