Final answer:
To find Karen's salary before the promotion, we can set up an equation based on the given information and solve for the original salary. The correct answer is c) $4802.
Step-by-step explanation:
To find Karen's salary before the promotion, we need to calculate the original salary using the given information. First, we know that Karen received a 12% salary increase. Let's represent the original salary as 'x'. The new monthly salary after the increase is $5388, so we can set up the equation: x + 0.12x = $5388. Simplifying this equation, we get 1.12x = $5388. Dividing both sides of the equation by 1.12, we find that the original salary, x, is approximately $4802. Therefore, the correct answer is c) $4802.