Which of the following BEST describes a private key in regards to asymmetric encryption?

Which of the following BEST describes a private key in regards to asymmetric encryption?

A.
The key owner has exclusive access to the private key.

B.
Everyone has access to the private key on the Ca.

C.
Only the CA has access to the private key.

D.
The key owner and a recipient of an encrypted email have exclusive access to the private key.