Answer:
C.

Explanation:
We have been given that the area of a hexagon is 42 square centimeters. We are asked to find the area of the hexagon, when all the dimensions of the hexagon are multiplied by 3.
We will use area of hexagon formula to solve our given problem.
, where a is length of each side of hexagon.
Since in the area of hexagon formula we square the length of each side of hexagon, so the area of the new hexagon would be square of 3 times the area of original hexagon.



Therefore, the area of new figure would be 378 square centimeters and option C is the correct choice.