DEF Corporation, a CFC$,$ has Subpart F income of $$300,000,$ consisting of foreign Uase company services income. DEF paid $$75,000$ in foreign taxes on the income. The U$.$S$.$ shareholder's pro rata share of DEF Corporation's Subpart F income is $$90,000.$ If the U$.$S$.$ shareholder is a corporation, what is the maximum amount of foreign tax credits the corporatio can claim on the Subpart F income?

a$)$ $$90,000$

d$)$ $$18,900$

b$)$ $$63,000$

e$)$ None of the above

c$)$ $$22,500$