Which of the following types of redundancy prevents attacks in which an attacker can get physical control of a machine, insert unauthorized software, and alter data?

Data redundancy primarily focuses on having multiple copies of data to ensure availability and integrity against data loss, not directly against physical machine compromise and unauthorized software insertion.

Hardware redundancy involves duplicating physical components to ensure availability if one fails, but it doesn't inherently prevent an attacker with physical access from inserting unauthorized software or altering data on the compromised hardware.

Process redundancy involves having multiple, often isolated, instances of a process or system running, or distributing the processing across different, independent systems. If an attacker gains physical control of one machine, inserts unauthorized software, or alters data on it, the redundant processes or separate systems can continue operations securely or detect inconsistencies, effectively preventing the attack from compromising the entire system or service.

Application redundancy ensures an application remains available by running multiple instances, but if an attacker can compromise the underlying operating system or gain physical control, this does not prevent them from inserting unauthorized software or altering data.