If you were shown one photograph of pumice and one of granite, how could you distinguish between the two rocks?

The pumice has gas trapped inside it so it has many holes, while Granite has quartz, feldspar, calcite and mica so it has many colors to it. The crystals in granite provide a variety of mixed colors — feldspar (pink or red), mica (dark brown or black), quartz (clear pink, white, or black) and amphibole (black).

allowed for the prediction of the properties of missing elements.

b is the correct answer