Answer:
18.85 
*You should run the numbers yourself as well. Sometimes different calculators will get marginally different numbers or use a different rounding for
that gives a slightly different answer*
Step-by-step explanation:
Surface area of a cylinder: 
Where h is the height and r is the radius. Remember that the radius is half the diameter, and the diameter is a straight line that passes through a circle.
I could be wrong, but I think you had the correct equation but used the diameter in stead of the radius to get 50.36.
Radius: 1 Height: 2
Plug numbers into equation:

I hope that helps!