Lengths of five edges of a tetrahedron are 1, while the last one is x. Its volume is F(x). On its domain of definition, we have
(A) F(x) is an increasing function, it has no maximum value.
(B) F(x) is an increasing function, it has maximum value.
(C) F(x) is not an increasing function, it has no maximum value.
(D) F(x) is an increasing function, it has maximum value. functiongeometry3D geometrytetrahedron