It isn't specific TRUE. What effects? It doesn't say.
It's vague TRUE. Are these positive or negative? Is this for all homeschooling kids or just certain grades?
It's subjective FALSE. Tricky, because this could be a thesis for a subjective essay (your opinion) in which case the statement being subjective does NOT make it "weak". Or, if this essay is filled with statistical data as proof and not just your opinion, then it wouldn't be subjective anyway. This is the correct answer!
It doesn't take a stand TRUE. The statement doesn't say if there is a positive or negative effect. When you are writing an essay, the thesis should contain some kind of statement that you have to prove in the body of the essay. If there is nothing to prove, then you don't have an essay.