'Uncouth' means uncultured, or rough and coarse in manners. Options a, c and d are ruled out as they give words that pertain to crudity in appearance only. A person who is 'ungraceful' lacks grace or elegance; and, may not be pleasing to the eye, but is not necessarily crude in manners. 'Slovenly' and 'Unkempt' refer to untidy, messy appearance.