Atree has a height of 18 feet and casts a shadow that is 6 feet in length. a boy, standing at the base of the tree’s shadow, has a height of 4 feet. how long is the shadow cast by the boy?

The two triangles of this statement are similar, so:

height of the three / its shadow = height of the boy / it shadow

18 / 6 = 4 / x => x = 4*6 / 18 = 24 / 18 = 4 / 3

Convert to mixed number: 4 / 3 = 1 and 1/3.

So, the answer is the option A.