Which type of selection on a polygenic trait increases variation in the trait

The answer is Mutations.  It is the type of selection on a polygenic trait that increases variation in the trait.  Mutations increase genetic variation, which is needed for natural selection to bring about evolutionary change.  When a cell divides, it makes a copy of its DNA — and sometimes the copy is not quite perfect. That small difference from the original DNA sequence is a mutation. 

You should provide a picture to show where the arrow is pointing and which information that is given. but there are 3 branches of the government, legislative, executive, and judicial. legislative makes laws, executives pass laws, and judicial are the courts