which pair of fractions is proportional

A)0.8/0.4=3.2/2
B)0.6/0.3=0.9/0.45
C)0.8/0.4=3.2/2.4
D)0.8/0.4=4/2.4

I thought B was correct. to get this i multiplied 0.6 *0.45=.27
multiplied 0.3 *0.9=.27
Am I on the right track?
I multiplied the opposites of each fraction in each problem.

0.6 / 0.3 = 2

0.9 / 0.45 = 2
The 2 ratios are egual and
therefore, proportional.
ANS = B.