Treetop Plant Services completed a special landscaping job for John Smith. Treetop uses ABC and has the following predetermined overhead allocation rates: Activity Designing Planting Allocation Base Number of designs Number of plants Predetermined Overhead Allocation Rate $230 per design $16 per plant The John Smith project required $1,800 in landscape materials, $600 in direct labor, one design, and 55 plants. If Treetop charged $4,700 for the job, what is the operating income? OA. $1,190 OB. $960 OC. $1,790 OD. $3,220