What are the security issues that arise in the use of the NFS (Network File System)?

What are the security issues that arise in the use of the NFS (Network File System)?

A.
Synchronization of user and group IDs is poor, so it is easy to spoof trusted hosts and user names.

B.
The lack of logging in one place or on one machine, and the multiple logs this then requires, can create bottlenecks

C.
The possibility arises for Cleartext passwords to be sniffed on the network if it does not use Secure RPC.

D.
NFS uses a weak authentication scheme and transfers information in encrypted form

Explanation:
Since the authentication is weak, it is easy to break into the session and spoof node addresses.
Incorrect Answers:
B: Logging bottlenecks are a performance issue, not a security issue.
C: The passwords are not cleartext, although the authentication algorithm is weak.
D: NFS was not designed with security in mind. NFS suffers from a poor authentication algorithm.NFS requests can be easily spoofed. However, data is not encrypted.