Order the following numbers from least to greatest: 4.06, 4.6, 4.72, 4.59.

a 4.06, 4.59, 4.6, 4.72
b 4.59, 4.06, 4.6, 4.72
c 4.72, 4.6, 4.59, 4.06
d 4.72, 4.6, 4.06, 4.59