Which is the primary difference between symmetric and asymmetric encryption?

Question $25$ options:

Symmetric encryption is a one$-$way function, meaning something that has been encrypted using symmetric encryption cannot be decrypted. Asymmetric encryption is a two$-$way function.

Symmetric encryption uses the same key single secret key for encryption and decryption, whereas asymmetric encryption uses a key pair consisting of a public key and a private key.

There is no major difference other than symmetric encryption is the predecessor to symmetric encryption.

Asymmetric encryption requires only a single private key, whereas symmetric encryption requires the use of more than one private key.

Symmetric encryption requires that the key that is used must be a palindrome. Asymmetric encryption keys do not have to adhere to this requirement and are therefore easier to generate.