Final answer:
The Number lock key is activated in order to use the numeric keypad.
Step-by-step explanation:
The correct answer is option C. The Number lock key is activated in order to use the numeric keypad.
When the Number lock key is activated, the numeric keypad on the right side of the keyboard can be used to enter numeric values. The Number lock key toggles between the keypad functioning as a set of numbers or as navigational keys.