YOu're right ,,and also im right
ALi has been studing and has studied and had studied ,,, they are all correct ,, because you didn't specify the question more ,,,
If you for instance said ,,,
Ali _____ in ksa for 5 years.However,he just got graduated.
You can say here has been studied ( because he just finished studying,he just graduated )
Ali _____ in ksa for 5 years.Now,he works in a huge technological company
You can say here has studied (because you just don't know probably when he finished studying )
