The employers should have mercy ...

The employers should have mercy on the employees. That is to say, the employers should be _____ them.
A. merciful to B. merciful on C. mercy to D. mercifully to

What;s the bbc ? Employers wouldn't mind a little.... the sun shine(s) one the earth Where's the bookshop in the u.s.a? what's the difference ? Wht's the mean what's the matter? he's the one where's the recorder? The Love's End