How Do Humans Use Their Eyes to Measure Relative Distance

How do humans use their eyes to measure relative distance by parallax?

A) By continuously focusing our eyes on distant objects, we can determine distance.
B) Since our eyes are separated, the brain interprets the relative look angles of the two eyes in terms of distance to the object viewed.
C) Our eyes can measure the time it takes light to travel from an object, and from this we get distance.
D) As we move our heads from side to side, our brain compares look angles from each of these positions to work out the distance to the object viewed.