I might go with d it seems right to me hope this helps.
D. A disadvantage of nuclear power is that waste products are unsafe and hard to store. They must be stored for many hundreds of years before they becomes safe and easier to dispose of, and we currently don't have a good method of storing them in the meantime.
Answer:
Silver
Explanation:
I remember this because Ag can mean "Ain't Gold"
The rock cycle is referred to as cycle because it repeats over and over again. The definition of cycle is a series of events that are regularly related in the same order. So with the rock cycle they stay in the same order and repeat.
Hope this helps :)
