Which of the following wireless standards uses direct sequence spread spectrum (DSSS) by default? A. Bluetooth B. 802.11a C. 802.11b D. 802.11ac Solution C. 802.11b uses direct sequence spread spectrum (DSSS) technology. DSSS is a transmission method that transmits the data along with a chipping bit to increase the signal’s resistance to interference. Answer A is incorrect because Bluetooth uses frequency-hopping spread spectrum. Answer B is incorrect because 802.11a uses orthogonal frequency-division multiplexing. Answer D is incorrect because 802.11ac uses MIMO-OFDM.