Delimiter flag : 0111 (we stuff 0 after every 011)
Data sequence send by sender : 01110110
Data to be sent : 0110101100
you have marked 011010110 which is wrong, when receiver receive the data, he will remove 0 after every 011, so he will receive data as 0111011, which is not match with data sent by sender. So data loss is present here.
Option D is correct.