A Customer Needs an 802

A customer needs an 802.11ac upgrade for an office with cubicles. The customer states that, because they planned locations for the existing 802.11n APs so that there are no coverage holes, they will simply deploy the new 802.11ac APs in the same location as the existing APs. The customer plans to support mobile devices in addition to laptops. What should the architect explain about shy a site survey is desirable to determine the optimal locations for the new APs?

A) An 802ac deployment typically works better with side-mounted, rather than ceiling-mounted, APs, and a site survey will help determine the new mounting locations.
B) The new 802.11ac deployment should have a capacity-based design for the best performance, but the existing deployment sounds like a coverage-based design.
C) 802.11ac AP radios tend to be more sensitive to 2.4 GHz interference than 802.11n APs, so the architect needs to search for all potential sources of such interference.
D) 802.11ac APs can support a higher density of clients, so they can be deployed farther apart than the APs in most existing 802.11n deployments.