What are two risks when using a source-based RTBH solution? (ChooseTWO)

What are two risks when using a source-based RTBH solution? (ChooseTWO)
A . The attacker address could be a CGNAT address resulting in a larger service outage for users.
B . The target of the attack may not support RTB
D . The attacker’s address could be unknown.
E . The target of an attack would be blocked resulting in a target being offline.

Answer: A,B