Business English 10th Edition by Mary Ellen Guffey,Carolyn Seefer

Exercise 71

After each sentence write the letter representing the correct word in the space provided. Remember that the relative pronoun which should be used only to introduce nonessential clauses and, as such, requires commas. Also remember that who , whom , and whose are used to refer to persons. That and which refers to animals or things.
The IRS, (a) who, (b) that, (c) which audits only 2 percent of all income tax returns, is choked with paperwork. _______________