If y=f(u)y = f(u)y=f(u) and u=g(x)u = g(x)u=g(x), then dy/dxdy/dxdy/dx is:
(dy/du)⋅(du/dx)(dy/du) \cdot (du/dx)(dy/du)⋅(du/dx)
dy/dxdy/dxdy/dx
f′(g(x))g′(x)f'(g(x))g'(x)f′(g(x))g′(x)
Both a and c