You have an Azure subscription that contains a key vault named Vault$1.$

You plan to store the following keys in Vault$1$:

$$ Key$1,$ which is RSA key type.

$$ Key$2,$ which is RSA$-$HSM key type.

$$ Key$3,$ which is EC P$-256$ key type.

$$ Key$4,$ which is EC P$-521$ key type.

Which key can be marked as exportable?

Key$1$

Key$2$

Key$3$

Key$4$