What are the differences between SSL and S-HTTP?

A.
SSL operates at the network layer and S-HTTP operates at the application layer

B.
SSL operates at the application layer and S-HTTP operates at the network layer

C.
SSL operates at the transport layer and S-HTTP operates at the application layer

D.
SSL operates at the application layer and S-HTTP operates at the transport layer

Explanation:
The main difference between the protocols is the layer at which they operate. SSL operates at the transport layer and mimics the "socket library," while S-HTTP operates at the application layer. Encryption of the transport layer allows SSL to be application-independent, while S-HTTP is limited to the specific software implementing it. The protocols adopt different philosophies towards encryption as well, with SSL encrypting the entire communications channel and S-HTTP encrypting each message independently.