You Discover a Binary Star System in Which Star a Has

You discover a binary star system in which star A has a velocity of 10 km/s and star B has a velocity of 30 km/s. If you study the system further and find out that the orbital period is 30 days and the orbital separation is a constant 0.3 AU, then what are the masses of stars A and B?

A) Star A is 3M _$\odot$ , and Star B is 1M _$\odot$ .
B) Star A is 1M _$\odot$ , and Star B is 0.3M _$\odot$ .
C) Star A is 6M _$\odot$ , and Star B is 2M _$\odot$ .
D) Star A is 2M _$\odot$ , and Star B is 0.5M _$\odot$ .
E) Star A is 0.3M _$\odot$ , and Star B is 1M _$\odot$