Verbatim Company budgeted $80,000 of factory overhead cost to manufacture 1,000 units in 2010. At the end of 2010, the company found out that it manufactured only 850 units. Verbatim spent $80,000 on factory overhead in 2010. Did the plant manager do a good job in controlling factory overhead cost if (a) the company had only fixed factory overhead, or (b) the budgeted factory overhead figure included $60,000 of variable factory overhead cost?