In the rock cycle a. there is only type of source material that can be used to make an igneous rock b. you cannot make a metamorphic rock from a sedimentary rock. c. any type of rock can become another type of rock, but specific events have to occur. d. does not apply to events that occur in the crust.

The answer is c. any type of rock can become another type of rock, but specific events have to occur.

In the rock cycle,any type of rock:

Intrusive igneous rock(plutonic rock), Extrusive igneous rock(volcanic rock), Sedimentary rock and Metamorphic rock can all become one another.

Let's start with sedimentary rock as an example:

Sedimentary rock,after compaction or under extreme heat,would turn into metamorphic rock.
The metamorphic rock which meets the magma under the subduction if plates would them melt, and turn into magma. When magma erupted from the volcano as lava and cools down,it turns into either plutonic or volcanic rock.

Therefore c. is the correct answer.

Hope it helps!