Which statement$($s$)$ is correct regarding foreign tax credits?

a$)$ If you volunteer to pay a foreign income tax you can still take it as a foreign tax credit

b$)$ A US taxpayer can never take a deduction for foreign income taxes paid

c$)$ Foreign tax credits could be limited and can only be credited against the US tax liability on net foreign source income

d$)$ All of the above.

e$)$ Both A and B