He had an ________habit of emptying ash trays out of his upstairs window onto our doorstep.
句意：他有个讨厌的习惯，就是把烟灰缸从楼上的窗户倒到我们的门口。 objectionable令人讨厌的。afflicting痛苦的。uneducated无教养的。offending冒犯的。因此，本题的正确答案为A。