A company has long$-$term assets of $$2,000,$ current liabilities of $$1,250,$ and long$-$term liabilities of $$1,500.$ If the current ratio is $2\mathrm{.}5,$ then current assets must be

a$.$ $$3,125.$

b$.$ $$1,563.$

c$.$ $$5,000.$

d$.$ $$500.$