The correct answer is B - Elliptic Curve Diffie-Hellman (ECDH).
WGU Cybersecurity Architecture and Engineering (KFO1 / D488) material highlights that ECDH is an enhanced, more efficient form of the traditional Diffie-Hellman key exchange, using elliptic curve cryptography (ECC). It provides similar security with much smaller key sizes, improving performance and efficiency.
DH (A) is the traditional method but is less efficient. RSA (C) is primarily used for encryption and digital signatures. DSA (D) is used for digital signatures, not for key exchange.
Reference Extract from Study Guide:
"Elliptic Curve Diffie-Hellman (ECDH) enhances traditional key exchange by utilizing elliptic curve cryptography, offering higher security with smaller key sizes and improved efficiency."
- WGU Cybersecurity Architecture and Engineering (KFO1 / D488), Cryptographic Key Management