Answer: 1. multiplication
Step-by-step explanation:
Suppose that you want to change an object with length L with a scale factor a, then the lenght of the rescaled object will be:
L' = a*L
Then the correct option is 1) multiplication.
Notice that sometimes you may find that the scale factor is a number like 1/5 and when you find the new lenght you will end with something like:
L' = L/5 that seems like a division, but this is actually the multiplication between L and 1/5.
