Final answer:
The absolute value of -6 is the distance from zero, which is 6 units. Thus, |-6| evaluates to 6.
Step-by-step explanation:
The absolute value of a number is its distance from zero on the number line, regardless of the direction. To evaluate the expression |-6|, you need to determine how far the number -6 is from zero without considering the direction. Since -6 is 6 units away from zero, the absolute value of -6 is 6. Therefore, the correct answer is a) 6.