Which of the Following Is True About Nissl Staining

Which of the following is true about Nissl staining?

A) This technique led to the theory of the neuron doctrine by Franz Nissl.
B) It is a staining technique done in order to distinguish neurons from other cells in the brain by staining the cell body.
C) This is a staining technique done by soaking tissue in silver chromate in order to make neurons appear in a dark colour.
D) The discovery of this technique 20 years ago has made more advances in knowledge of neuroanatomy than the previous 100 years combined.
E) All of the above are true.