Explain how a vector field F (f.g,h) is used to describe the motion of the air in a room at one instant in time. Choose the correct answer below.
A. F = (f,g,h) evaluated at (x,y,z) is the location vector of an air particle at (x,y,z) at a fixed point in time
B. F = (f,g,h) evaluated at (x,y,z) is the velocity vector of an air particle at (x,y,z) at a fixed point in time.
C. The gradient of F = g, h> evaluated at (x,y,z) is the location vector of an air particle at (x,y,z) at a fixed point in time.
D. The gradient of F= (f.g.h) evaluated at (x.y,z) is the velocity vector of an air particle at (x.y,z) at a fixed point in time.