The invasion of unwelcome species can be stopped at all of the following points except

(a.) before reproduction

(b.) after they are found

(c) before the introduction

(d) after they are established

Option D

Explanation:

The unwelcome species or the invasive species can be stopped by entering into a new place by killing them at proper time.

They can be prevented from entering into a new place by various means, they can also be stopped from reproducing and giving birth to new ones so that they cannot conquer the area.

They can be killed once they are found and these are some of the ways by which they can be prevented from entering into a new place.

1. efficient use of space

2. elimination of groundwater contamination

3. energy generation

4. lower carbon footprint

multiple allele inheritance is traits controlled by more than 2 alleles (ex: pigeons having 3 alleles of one gene govern their feather color).   so the answer is a.