Show Zone of Impact-Displays the approximate interference impact area. The opacity of the circle denotes its severity. A solid red circle represents a very strong interferer that likely disrupts Wi-Fi communications, a light pink circle represents a weak interferer.
We can see an area where the circles overlap and create what is close to a solid red circle, however the fact that each lightning bolt has a number greater than 1 this makes B the best choice as they seem to want to put emphasis on the number of interferers rather than the severity.
https://www.cisco.com/c/en/us/td/docs/net_mgmt/prime/infrastructure/3-
7/user/guide/bk_CiscoPrimeInfrastructure_3_7_0_User_Guide/bk_CiscoPrimeInfrastructure_3_7
_0_User_Guide_chapter_01001.html

Choose Controller > General to configure AP multicast mode (multicast or unicast) & CAPWAP multicast group address(only for multicast mode). Use private multicast IP (239.0.0.0/8) for the group address, but avoid 239.0.0.x or 239.128.0.x as these overlap with the link local MAC addresses & flood out all switch ports. This group address cannot be used for any application in your network. If you have multiple controllers, configure different group address for different controllers.
https://mrncciew.com/2012/11/17/configuring-multicast-on-wlc/

Explanation
A Cisco OfficeExtend access point (Cisco OEAP) provides secure communications from a Cisco WLC to a Cisco AP at a remote location, seamlessly extending the corporate WLAN over the Internet to an employee's residence. The user's experience at the home office is exactly the same as it would be at the corporate office.
Datagram Transport Layer Security (DTLS) encryption between the access point and the controller ensures that all communications have the highest level of security.Cisco OEAPs are designed to work behind a router or other gateway device that is using network address translation (NAT). NAT allows a device, such as a router, to act as an agent between the Internet (public) and a personal network (private), enabling an entire group of computers to be represented by a single IP address. There is no limit to the number of Cisco OEAPs that you can deploy behind a NAT device.
https://www.cisco.com/c/en/us/td/docs/wireless/controller/72/configuration/guide/cg/cg_flexconnect.html#wp12