Exhibit 6-8 Bea's Total utility of 3-minute telephone calls Quantity of 3-Minute Calls Total Utility of Telephone Calls 0 0 1 15 2 28 3 38 4 45 5 50 6 48 Refer to Exhibit 6-8. Diminishing returns set in after which telephone call? Show answer choices The first. The second. The third. The fifth. The sixth