Which of the following wireless standards uses frequencyhopp

Which of the following wireless standards uses frequency-hopping spread spectrum (FHSS) by default?

A. Bluetooth

B. 802.11a

C. 802.11b

D. 802.11g

Which of the following wireless standards uses frequency-hopping spread spectrum (FHSS) by default?

A. Bluetooth

by using this it avoid unwanted frequnecies in the sequence of hopping .it is much easier to implement
with fhss than dsss