Waterway Industriess high and low level of activity last year was 63000 units of product produced in May and 28000 units produced in November. Machine maintenance costs were $217600 in May and $105600 in November. Using the high-low method, determine an estimate of total maintenance cost for a month in which production is expected to be 51000 units.

a. $194400

b. $179200

c. $175200

d. $201600