Answer:
The correct option is, d) “All the statements are correct”.
Step-by-step explanation:
WiMAX (which in full means Worldwide Interoperability for Microwave Access and it is a family of wireless broadband communication standards that is based on the IEEE 802.16 set of standards, it makes provision for the use of multiple physical layer (PHY) and Media Access Control (MAC) options.) uses OFDM to carry data and increase spectral efficiency. It uses QAM and QPSK for adaptive modulation.