The height of a tennis ball tossed into the air is modeled by h(x) = 40x – 16x 2, where x is elapsed time in seconds. During what time interval will the tennis ball be at least 15 feet above the ground?

x > 0.5 seconds and x > 2.04 seconds
x > 0.5 seconds and x ≤ 2.04 seconds
x ≥ 0.5 seconds and x > 2.04 seconds
x ≥ 0.5 seconds and x ≤ 2.04 seconds