Final answer:
The statement '4 lies to the right of -2 on a number line' must be true based on the inequality -2 < 4.
Step-by-step explanation:
a) 4 lies to the right of -2 on a number line.
Based on the inequality -2 < 4, we can see that 4 is greater than -2.
To represent this on a number line, we would place 4 to the right of -2.
Therefore, the statement must be true.