Which two ways could CK use Chatter to solve this problem?

Cloud Kicks (CK) switched to Lightning Experience and started using Chatter across its global workforce to support its fast-paced sales cycle. CK loves Chatter but struggle with gathering feedback from core team members, including understanding who is available to respond.

Which two ways could CK use Chatter to solve this problem? Choose 2 answers
A . Streams
B. Polls
C. Out of Office
D. Topics

Answer: B,C