First of all, you have to compare the two instances. So if 1000g makes 1kg. Then how many grammes will make 4kg
1000g=1kg
x=4kg.
I represented the unknown with (x)
So you make 1 multiply x and 4 multiply 1000
1x=1000x4
1x=4000
1x is the same as x. So
x=4000g
Which is A. Hope I helped.
