Which one?
A. B. C. or D?

The point where two air masses meet is called a

Rocks that contain crystals that are roughly equal in size and can be identified with the unaided eye are said to exhibit a texture.

Read the article titled "trans-saharan migration routes to north africa and the eu: historical roots and current trends." why do tens of thousands of sub-saharan africans try to cross the mediterranean each year? how are these refugees commonly portrayed? (site 1)