The electromagnetic spectrum consists of many different waves. what is the order of these ways from lowest to highest frequency?

The order of the waves in the electromagnetic spectrum from lowest to highest frequency is:
radio waves     < 3 x 10^9 hz
microwaves           3 x 10^9 hz - 3 x 10^12 hz
infrared radiation   3 x 10^12 hz - 4.3 x 10^14 hz
visible light rays     4.3 x 10^14 hz - 7.5 x 10^14 hz
ultra violet radiation   7.5 x 10^14 hz - 3 x 10^17 hz
x-rays                       3 x 10^17 hz - 3 x 10^19 hz
gamma rays           > 3 x 10^19 hz

Letter a i’d go with