Final answer:
The part of a computer that needs up-to-date definitions is the Antivirus Software. These definitions help the software identify and protect against the latest malware threats. Hardware components such as the CPU, RAM, and hard drive do not use definitions.
Step-by-step explanation:
The part of a computer that relies on up-to-date definitions is the Antivirus Software. Antivirus software is designed to detect, prevent, and remove malware, including viruses, worms, and trojans. To do so effectively, it needs to have the latest definitions of what constitutes malware, which are constantly updated to include new threats as they are identified by cybersecurity experts. Therefore, keeping the antivirus definitions up-to-date is crucial in order for the antivirus to recognize and protect against the most recent threats.
Neither the CPU (Central Processing Unit), the RAM (Random Access Memory), nor the hard drive relies on definitions. These components are hardware parts of a computer which perform processing, temporary storage of data, and long-term storage of data respectively. Therefore, the correct answer to which part of a computer needs up-to-date definitions is D. Antivirus Software.