which of the following?

MSP, PGP, PEM, and S/MIME are examples of which of the following?

A.
Digital signing algorithms

B.
E-mail standards

C.
Asymmetric cryptography algorithms

D.
Hashing standards

Explanation:
These are examples of different e-mail standards:
MSP (Message Security Protocol)
PGP (Pretty Good Privacy)
PEM: (Privacy Enhanced Mail)
S/MIME (Secure Multipurpose Internet Mail Extensions)