Assertion. Crackers and hackers technically do the same thing.

Reason. Crackers do the hacking with malicious intentions to harm the data or system while hackers do the hacking with good intentions to know more about the system or to safeguard it.

(a)

Both Assertion and Reason are true and Reason is the correct explanation of Assertion.

Explanation
Both hackers and crackers do the same thing, i.e., hack a system but with different intentions. Hackers are technically sound people who hack devices and systems with good intentions, such as to find the security lapses of a system, in order to rectify it or for obtaining more knowledge out of it. But crackers are technically sound people with malicious intentions who hack a system by breaking into it and violating it for some bad motives.