Which statement is true?
a. venus shows evidence of recent volcanic and tectonic activity.
b. venus is the only planet that has water in all three of its states.
c. venus has the greatest temperature extremes of any planet.

Hello! We know that water boils at 100 °C. The surface of Venus is 461.85 °C. If you take this into effect, we know that water can't be on the surface of the planet! Venus is the hottest planet in the solar system, however, Mercury has the most extreme temperatures. So, when you cancel these out that should leave you with your answer! 

I hope this helped!

I am, yours most sincerely,
SuperHelperThingy