Pablo was reviewing the water bill for his carwash business and determined that the highest bill, $5,000, occurred in July when 4,000 cars were washed and the lowest bill, $4,000, occurred in February when 2,000 cars were washed. What was the fixed portion of the water bill? OA. $2,000 OB. $3,000 OC. $4,000 O D. $1,000