The following data relate to direct labor costs for the current period:Standard costsActual costs$9,000$ hours at $$5\mathrm{.}508,500$ hours at $$5\mathrm{.}75$The direct labor rate variance isO a$.$ $$2,250$ unfavorableO b$.$$$2\mathrm{.}125$ unfavorableO c$.$ $$2\mathrm{.}125$ favorableO d$.$ $$2,250$ favorable