What is the difference between basic IS-IS and OSPF packet types?

What is the difference between basic IS-IS and OSPF packet types?
A . IS-IS and OSPF use area packets, but only IS-IS uses sequence number packets.
B. IS-IS and OSPF use link-state update packets, but only OSPF uses link-state ACK packets.
C. IS-IS and OSPF use Hello packets, but only OSPF uses DBD packets.
D. IS-IS and OSPF use link-state update packets, but only IS-IS uses DBD packets.

View Answer

Answer: C

Explanation:

Reference: https://www.ciscopress.com/articles/article.asp?p=26850&seqNum=4