Abel is not sure why, from h = vi2 sin2 θi 2g , the height the tennis ball reaches is maximum when θi = 90°, and asks Kato to explain. Which of Kato's responses is correct? "When θi = 90°, sin2 θi = sin(2θi) = 1, which is its maximum value, so h is maximum." "When θi = 90°, sin2 θi is maximum, so h is maximum." "When θi = 90°, sin θi = 1, sin2 θi = 2 · 1 = 2, which is its maximum value, so that means h is maximum." "When θi = 90°, sin2 θi is minimum, so h is maximum."