Answer:
The surface area of the new prism increased by less than a scale factor of two.
Explanation:
original prism: S.A. = SA of 4 sides + Top + Bottom = 4(9x6) + 2 (3x6) = 252
scaled up prism: SA = 4(18x6) + 2(3x6) = 468
height = 2(9) = 18
468/252 = 1.857 < 2