given answers are correct

The given answer is correct. Anycast addresses can be used only by a device, not a host. https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/ipv6_basic/configuration/xe-3se/5700/ip6-anycast-add-xe.html

Anycast addresses CAN be used as source address. If an anycast address is contacted, the reply has that anycast address as the source.

I think that the given answer is wrong. An Multicast address can be used as an source address.

I think this may be wrong? i dont think multicast or anycast can be used as a source address?

Correct

Anycast: is assigned to more than one interface is used exclusively by a non-host device Multicast: cannot be used as a source address provides one-to-many communications

Anycast: is assigned to more than one interface is used exclusively by a non-host device Multicast: cannot be used as a source address provides one-to-many communications

IPv6 multicast addresses use the prefix ff00::/8, shown in Table 4-10, which is equivalent to the IPv4 multicast address 224.0. 0.0/4. A packet sent to a multicast group always has a unicast source address. A multicast address can never be the source address. https://www.ciscopress.com/articles/article.asp?p=2803866&seqNum=5#:~:text=IPv6%20multicast%20addresses%20use%20the,never%20be%20the%20source%20address.

Anycast It is assigned to more than one interface It cannot be used as source address Multicast provides one-to-many communication It is used by exclusively non-host device