The correct option is
B Manageable
'Docile' means easy to control or do.
Option A - 'Vague' means not clearly expressed. Thus option A is incorrect.
Option C - 'Stupid' means silly or unwise. Thus option C is incorrect.
Option D - 'Stubborn' means a person who is determined to do that he is or she wants and refuses to do anything else. Thus option D is incorrect.
Option B - 'Manageable' means easy or possible to do or deal with. Thus option B is the correct answer.
'Docile - Manageable'