Explanation

A good tree brings forth good fruit.

A good tree brings out good fruit.

Forth - The meaning of forth is to come out of some place or simply to out or away.

Out - The meaning if out according to the sentence given is to come out or grow.

• The given sentence tells you that a good grown tree will bring good fruit or will grow or give out good fruit.

So,

• According to the given sentence, both the words 'forth' and 'out' are correct, as both the words fulfils or shows the correct meaning of the sentence.