Before dropping room prices from$$ $$100$ to$$ $$90,$ the NoTell Motel rented $3$ rooms. Total costs were$$ $$150.$ After the price$$ drop, total costs increased to$$ $$240.$ The$$ motel's marginal costs of increasing output are

Question content area bottom

Part $1$

A$.$

$$$$60.$

B$.$

$$$$150.$

C$.$

$$$$50.$

D$.$

$$$$240.$

E$.$

$$$$90.$