(Which mechanism implemented in WPA-Enterprise guards against bit-flipping exploits?

Bit-flipping exploits target encryption modes or protocols that do not provide strong integrity, allowing attackers to modify ciphertext so that predictable changes occur in plaintext after decryption. To defend against this, protocols add an integrity mechanism that detects tampering. In WPA (including enterprise deployments), TKIP introduced a Message Integrity Check (MIC) called “Michael.” The MIC is computed over the frame contents (with additional fields) and verified by the receiver; if an attacker flips bits in transit, the MIC verification fails, and the frame is rejected. While AES (used by WPA2’s CCMP) also provides integrity via authenticated encryption, the option presented that directly names the tamper-detection mechanism associated with guarding against bit-flipping is MIC. A pre-shared key is an authentication/keying method (and not enterprise-mode anyway), and a “global encryption key” would be the opposite of what you want—global/static keys worsen security. Therefore, the intended mechanism that mitigates bit-flipping by detecting unauthorized modifications is the Message Integrity Check.