Two dolphins are catching fish when they begin moving to the surface to get a breath of air. they start swimming toward the surface at the same time. the first dolphin is 120 feet below the surface of the ocean, and he swims upward at a rate of 4 feet/second. the second dolphin is 240 feet below the surface, and she swims upward at a rate of 12 feet/second. which dolphin surfaces first and when? a. the first dolphin, after 10 seconds b. the first dolphin, after 30 seconds c. the second dolphin, after 15 seconds d. the second dolphin, after 20 seconds