How did Leonardo da Vinci use one-point perspective in this painting? Choose all answers that are correct.
a. He drew a horizon line to show where the sky and earth appear to meet.
b. He used a vanishing point to draw objects that run horizontally across the painting.
c. He used orthogonal lines to draw the sides of objects that run towards the vanishing point.
d. He made distanct objects larger than nearby objects.