Solution

"Brings out" typically means to reveal or display something that was hidden. It is not suitable in the context of a tree-producing fruit. "Brings in" usually implies bringing something into a place. This is not appropriate for describing the production of fruit by a tree. "Brings on" is used to indicate causing or initiating something, and it is not the right fit for describing the natural process of a tree bearing fruit. The correct choice is: “brings forth”. "Brings forth" is the most appropriate option for describing the act of a tree producing or yielding fruit. Therefore, the complete sentence is: "In the summer season, the mango tree brings forth fresh fruit."