Sharing my findings..
A. appeared — a red sash across her chest, a crown hugging the band of her cowboy hat; she rode in circles on her gray horse, waving at the crowd as if she knew each of them personally
B. appeared —
a red sash across her chest and a crown hugging the band of her cowboy hat;
she rode in circles on her gray horse and waving at the crowd as if she knew each of them personally- Green highlights are fine. Red one is incomplete(sentence fragment) and hence incorrect.
C. appeared — a red sash across her chest;
a crown hugging the band of her cowboy hat; she rode in circles on her gray horse and was waving at the crowd as if she knew each of them personally
- Again the one highlighted RED is problematic as it is a fragment.
D. appeared with a red sash across her chest, a crown hugging the band of her cowboy hat, she rode in circles on her gray horse, and was waving at the crowd as if she knew each of them personally
- here appreared with X(correct), Y(correct), she robe(wrong).. It should either be as below -
appeared with X and Y, and she robe..
appeared with X, Y and robe...
E.
appeared with a red sash across her chest and a crown hugging the band of her cowboy hat, rode in circles on her gray horse, waving at the crowd as if she knew each of them personally
- highlighted GREEN is fine. But "And" is missing before robe.
By POE, A seems best and hence the ANSWER.