What is the difference between a source tree and a shared tree in a multicast environment?

What is the difference between a source tree and a shared tree in a multicast environment?
A . To route traffic from source to receiver a source tree uses a link-state routing protocol and a shared tree uses a distance-vector routing protocol.
B . A source tree has its root at the source, and a shared tree has its root at a designated rendezvous point.
C . To stream multicast from source to receiver, a source tree uses PIM-SM and a shared tree uses PIM-D
E . Source trees are the default type for bidirectional PI
F . and PIM-DM uses shared trees by default.

Answer: B

Explanation:

Reference: https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/ipmulti_pim/configuration/xe-16-5/imc-pim-xe-16-5-book/imc-tech-oview.html