Arock has been formed by the accumulation of bits of rocks that were originally formed by the release of heat by magma. how should this rock be classified?

The rock can be classified as Sedimentary. This is kind of a trick question. The main question is a rock that has been formed by the accumulation of bits of rocks. That alone should give you a clue because sedimentary rocks are rocks that are made up of bits or particles of other rocks.

Now what about the part that says: were originally formed by the release of heat by magma?  

At first glance you might think, then that means it is an igneous rock, but no it isn't. It was originally an igneous rock but the rock in question is the rock that was formed by BITS of it. So this means that the resulting rock is SEDIMENTARY.