Which sentence does not contain any errors? a. their house was just painted blue. b. they're house was just painted blue. c. there house was just painted blue. d. theyre house was just painted blue.

The sentence that does not contain any errors is A.

B has "They're house" which is a contraction of "They are" and "They are house was just painted blue." is incorrect grammar.

C has "There house", There is not a possessive which is needed in this case, so it is also incorrect.

D is the same thing as A, except it does not have the apostrophe, making it even less correct

Hope this helped :)