Fact 1: Adult worms go through a major transformation to develop reproductive organs.

Fact 2: Marine flatworms belong to a major group of worms called the Platyhelminthes.

Given the two facts above, answer the question "When do platyhelminthes reproductive organs develop?" with the following options: 
- when they become adults
 - It helps them survive
 - produce offspring
 - By wind and rain
 - during the day
 - members of their own species
 - an area swollen with pus
 - Something coming from a gland


 

 when they become adults        