In a Recent Research Paper Published by the European Central

In a recent research paper published by the European Central Bank,two economists concluded that

A) tax revenue would increase in Denmark and Sweden if tax rates on capital income were reduced in those countries.
B) tax revenue would increase in Denmark and Sweden if tax rates on labor income were reduced in those countries.
C) tax revenue would increase in the U.S. if tax rates on capital income were reduced in the U.S.
D) tax revenue would increase in the U.S. if tax rates on labor income were reduced in the U.S.