Heller Cannery, Inc. uses a predetermined overhead rate based on machine-hours to apply manufacturing overhead to jobs. The company estimated that it would incur $510,000 in manufacturing overhead during the year and that it would work 100,000 machine-hours. The company actually worked 105,000 machine-hours and incurred $540,000 in manufacturing overhead costs. By how much was manufacturing overhead underapplied or overapplied for the year?
a) $4,500 overapplied
b) $4,500 underapplied
c) $30,000 overapplied
d $30,000 underapplied