B Is a Computer Systems Analyst for IBM Corporation Living

B is a computer systems analyst for IBM Corporation living and working in Dayton, Ohio.During the year, she drove to Cincinnati to help C with problems he was having on a recently purchased system.B spent the night in Cincinnati and ate by herself, spending $30 for dinner including $4 for a tip and $1 in tax.Under her per diem arrangement, she was reimbursed $20 for her meal.B's deduction, before application of the 2 percent of A.G.I.limitation for miscellaneous itemized deductions, is

A) $20
B) $24
C) $25
D) $28
E) $30