Which of the following sets of population interactions most likely lead to both co-evolution and co-extinction?

Many parasites have evolved to be host-specific (they can parasitise only a single species of host) in such a way that both host and the parasite tend to co-evolve; that is, if the host evolves special mechanisms for rejecting or resisting the parasite, the parasite has to evolve mechanisms to counteract and neutralise
them, in order to be successful with the same host species. In a co-extinction, when a host becomes extinct, the unique assemblage of parasitic species associated with it in an obligatory way also become extinct.

In coevolved plant-pollinator mutualism also, extinction of one invariably leads to the extinction of the other.