The answer is Sodium Chloride
I’ll like to answer but Where the question ?
Crystalline silica is a natural compound in the earth's crust and is a basic component of sand and granite. Silicosis is an incurable disease of the lungs caused by breathing crystalline silica dust. This dust can cause scar tissue to form in the lungs.
C. The presence of predators could cause natural selection because it would mean survival of the fittest.
The plant belongs to the group Angiosperm. Vascular plants with seeds could be cycads, Gingko, conifers, or angiosperms. Among those groups, only angiosperms have flowers.
The plant they found have colored, scented flowers which suggests that it could be pollinated by insects or birds. Colored flowers attract birds and insects. Color serves as a guiding mark. Talking of scent, it does not attract bird, but attracts insects. It also serves as the guiding mark.