$19.$ Alice is situated across the globe from Bob but would like to communicate confidentially with Bob using a shared secret key K$.$ K can be established using Diffie Hellman Key Exchange.

Group of answer choices

Alice can set up the shared secret key K with Bob using Diffie Hellman mechanism even if an intruder that listens but not manipulates messages is present between them

Alice may not be able to set up the shared secret key K with Bob using Diffie Hellman mechanism if an intruder that manipulates messages is present between them

Alice and Bob exchange messages in the clear $($without any encryption$)$ while setting up the shared key K using Diffie Hellman.

All of the above