The so-called light bulb is actually a heat bulb.

Which of the following statements about porosity is NOT valid?

A) the amount of water that can be stored depends on the porosity
B) porosity partly depends on size and shape of grains and clasts
C) better sorted sediments have more porosity than unsorted ones
D) fractures may be the only real porosity in some igneous rocks
E) all of these are valid