By default, the priority is 1 on all routers so we can set the OSPF priority of the hub to a value which is greater than 1 to make sure it would become the DR.

From the output, we learn that the current best path is from 10.57.255.11 (which includes "...valid, confed-external, best") and this path is 2 ASes away (64955 65003). Although there are some paths with only 1 AS away (path from 172.16.254.234 for example) but they were not chosen the best path so AS_PATH was not used to determine the best path -> Answers A and answer C are not correct.
All the paths in the output have metric of 0 and this is the lowest (best) value for this attribute. If we configure higher MED then it is less preferred over other paths -> Answer B is not correct.
Only answer D is left but LOCAL_PREF attribute should be configured with higher value to be preferred so we hope "lower LOCAL_PREF" here means higher value. But this is the best answer.

From the last line of the output, we notice that the result was "Invalid AUTHEN packet". Therefore something went wrong with the username or password.