What describes public$-$key encryption?

Each person generates a pair of keys: a public key and a secret key. People publish their public keys and keep their secret keys to themselves.

Each person generates a pair of keys: a public key and a secret key. People publish their private keys and keep their public keys to themselves.

Each person generates a private key. People exchange their private keys to read the messages.

Each person generates a public key. People exchange their public keys to read the messages.