Polyploidy instantly results in a new plant species because it

The correct answer for the question that is being presented above is this one: "d. all of the above." Polyploidy instantly results in a new plant species because it changes a species’ number of chromosomes. 

Here are the following choices:
a. changes a species’ number of chromosomes. 
b. produces a hardier species. 
c. causes mutations. 
d. all of the above