Final answer:
White hat hackers are professionals who hack into systems to improve security by finding vulnerabilities. The answer to the question is A) White. They are contrasted with black, grey, and blue hat hackers who have different motivations and levels of legality in their actions.
Step-by-step explanation:
Computer experts who attempt to hack into a network to ensure that it is protected against intrusions are called white hat hackers. The correct answer to the question is A) White.
White hat hackers are cybersecurity professionals who use their skills to help organizations and individuals by improving system security. This typically involves simulating attacks to identify vulnerabilities so that they can be addressed before a malicious hacker can exploit them. In contrast, 'black hat hackers' use their skills for illegal or unethical purposes, and 'grey hat hackers' operate somewhere in between, often without permission but not necessarily with the intent to do harm. 'Blue hat hackers' are usually outside security professionals hired to test systems before they go live.