Full disk encryption is MOST effective against which of the following threats?

Full disk encryption does not prevent a denial-of-service attack that destroys or overwrites data, as destruction does not require reading the data.

Eavesdropping via electromagnetic emanations (TEMPEST attacks) captures signals emitted by hardware components during active use, which occurs after decryption and is not mitigated by disk encryption.

Malicious code executes within the running operating system after the disk has already been decrypted and mounted, so disk encryption provides no protection against malware.

Full disk encryption encrypts all data on the drive at rest so that if a device is stolen or otherwise physically obtained, the data cannot be read without the correct credentials or key. This directly addresses the threat of hardware theft - even removing the drive and connecting it to another system yields only ciphertext. It is a primary control for laptop and removable media theft scenarios in enterprise security policies.