Which set of ordered pairs represents y as a function of x?
A. {(2, 3), (3,5), (3, -5), (-2, 8), (-2, -8)
B.{(1, 2), (2, 3), (3, 4), (3,5)}
C.{(1, 2), (2, -3), (3, 4), (4, -5)}
D.{(1,3), (1,5), (1,7), (1,9), (1, 11)}
Help me plzzz

Aspacecraft can attain a stable orbit 300 kilometers above earth if it reaches a velocity of 7.7 kilometers per second. the formula for a rocket's maximum velocity v in kilometers per second is vequalsminus0.0098tplusc ln upper r, where t is the firing time in seconds, c is the velocity of the exhaust in kilometers per second, and r is the ratio of the mass of the rocket filled with fuel to the mass of the rocket without fuel. find the velocity of a spacecraft whose booster rocket has a mass ratio of 20, an exhaust velocity of 2.1 km/s, and a firing time of 15 s. can the spacecraft achieve a stable orbit 300 km above earth?