What is the melting point of a substance? (a) The temperature at which a liquid melts

(b) The temperature at which a gas will completely boil away

(c) The temperature at which the solid state turns into a liquid state

The correct answer should be C. The temperature at which the solid state turns into a liquid state.
A doesn’t make sense (a solid needs to melt, not a liquid)
B is evaporation I would think.

The answer is : v = 55 + 8m plug in m = 25 v = 55 + 8(25) = 255 25 minutes after baxter begins filling the tank, the volume of water in the tank will be 255 gallons. slope: m = 8 gal/min for every min the water is on, the volume of water in the tank increases by 55 gallons. y-intercept: 55 (0,55) the initial volume of water in the tank was 55 gallons.

Where is the choices for the question?