The Two Stars in a Binary Star System Revolve Around $T$

The two stars in a binary star system revolve around each other with a certain period $T$ . Which of the quantities listed below is not likely to be a part of the formula for this revolution period?

A) $m_{1}, m_{2}$ (the masses of the stars in the system)
B) $r$ (the distance between the binary stars)
C) $\hbar$ (Planck's constant, which is generally associated with phenomena involving quantum mechanics)
D) $G$ (the universal gravitational constant)