Choose the most obvious difference between potassium feldspar and plagioclase feldspar.
O one has a reddish streak, the other has a green-black streak
O one has cleavage planes at 90 degrees, the other has cleavage planes at 56 and 120 degrees
O one has one cleavage direction, the other has three cleavage directions
O one has one cleavage direction, the other has two cleavage directions
O one has striations, the other does not
O one is harder than glass, the other is softer than glass
O one is light-colored, the other is dark-colored
O one is non-metallic, the other is metallic
O one shows cleavage, the other does not show cleavage