The side of a square are 4 meters. if you double the length of the side, how does this affect the area

If you were to find the area of the square originally 
it would lw= a 
4x4= 16 

so if we doubled the sides 
4x2= 8 they'd become 8 

now find the area of the doubled square 
8x8= 64 

to find out the amount by which it increased, divide the new area by the old area 
64/16 =4 
this means that doubling the side lengths, quadruples the area 

Ithink the answer is c but then again i'm probably wrong