Read the Following Argument, and Then Answer Multiple Choice Question

Multiple Choice

Read the following argument, and then answer multiple choice question.
"This is an unsatisfactory place to live, because unemployment nationally is running at a lower rate than it is here. The U.S. Department of Labor announced an 8.5% national rate of unemployment while the State Employment Security Commission has said that the local unemployment rate is 11.5%."
-"Because unemployment nationally is running at a lower level than it is here" functions as

A) grounds.
B) warrant.
C) backing.
D) claim.