An Azure subscription can be associated to multiple Azure Active Directory (Azure AD) tenants. is incorrect. An Azure subscription can only be associated with one Azure AD tenant at a time. While you can change which tenant a subscription is associated with, it cannot be associated with multiple tenants simultaneously.
You can change the Azure Active Directory (Azure AD) tenant to which an Azure subscription is associated is correct
When an Azure subscription expires, the associated Azure Active Directory (Azure AD) tenant is deleted automatically. is incorrect. The Azure AD tenant is independent of subscription status. When a subscription expires, the Azure AD tenant and its directory data remain intact and can be used with other active subscriptions.
None of the statements are correct is incorrect. This is incorrect because the second statement is true - you can change the Azure AD tenant to which a subscription is associated, following proper procedures and permissions.