A local little league has a total of 65 players, of whom 40% are left handed how many left handed people are there

So... it has degree of 7, so based on the fundamental theorem of algebrait can have at most 7 solutions

now.. you have −4, −4i, 2i  <--- there are two complex ones there

-4i or 0-4i  and 2i or 0+2i

now.. bear in mind that, complex solutions never come all by their lonesome, they come with their sister, the conjugate

thus, that means 0-4i comes with 0+4i and 0+2i comes with 0-2i

that makes only 5 roots though

that simply means that, the -4 one, has a multiplicity of 3

as far as the B) and C) sections, check Descartes Rule of Signs
which surely you've covered already