Butler Automotive Developed a New Diagnostic Testing Procedure That Is

Butler Automotive developed a new diagnostic testing procedure that is expected to increase sales by $10,000 per month.As more drivers bring in their vehicles,Butler expects to also do more oil changes and brake repairs.As a result,inventory levels of oil and brake parts must be increased by $5,000.Revenues from oil changes and brake jobs are expected to increase by $4,000 per month.An example of a synergistic effect from the new diagnostic testing procedure is the

A) increase in inventory levels of oil and brake parts.
B) increase in revenue of $10,000 per month for the diagnostic testing.
C) increase in revenues from oil changes and brake jobs of $4,000 per month.
D) increase in all activities totaling $19,000 per month.