What is the countermeasure Mike applied to defend against jamming and scrambling attacks?

Mike, a security engineer, was recently hired by BigFox Ltd. The company recently experienced disastrous DoS attacks. The management had instructed Mike to build defensive strategies for the company’s IT infrastructure to thwart DoS/DDoS attacks. Mike deployed some countermeasures to handle jamming and scrambling attacks .

What is the countermeasure Mike applied to defend against jamming and scrambling attacks?
A . Allow the usage of functions such as gets and strcpy
B . Allow the transmission of all types of addressed packets at the ISP level
C . Implement cognitive radios in the physical layer
D . A Disable TCP SYN cookie protection

Answer: D