ATM Point to Multipoint connections:

A.
Are always bi-directional because they use amendments to AAL5

B.
Are unidirectional

C.
Do not exist

D.
Are only supported in Service Interworking

Explanation:
Point-to-point connects two ATM end systems and can be unidirectional (one-way communication) or bidirectional (two-way communication). Point-to-multipoint connects a single-source end system (known as the root node) to multiple destination end systems (known as leaves). Such connections are unidirectional only. Root nodes can transmit to leaves, but leaves cannot transmit to the root or to each other on the same connection. Cell replication is done within the ATM network by the ATM switches where the connection splits into two or more branches.