Which arrow represent process in the rock cycle that require heat and pressure?

The arrows pointing to the metamorphic rocks are the ones that represent processes that require heat and pressure. The rock cycle is a term that refers to the process of the transitions among the three main rock types: sedimentary, metamorphic, igneous. It shows how these rock types are related to each other. High temperature and pressure can change rocks physically and chemically and turn them into metamorphic rocks. 

Iam not sure but to me it with be a or dsorry if i was late! hope this ! : )if you really want me to find out the answer that is correct tell me and i will do more research but the a or d makes sense to me.