The Gas Motions Within Granules on the Solar Surface Are

The gas motions within granules on the solar surface are

A) upward in the centers of some cells and downward in the centers of others; the gas cools as it passes over the boundaries between cells.
B) upward in the bright cell centers and downward around the darker edges.
C) downward in the bright cell centers and upward around the darker edges.
D) almost nonexistent; the dark patterns represent a network of absorbing gases overlying the photosphere.