grinols is primArily ConCErnED with _________in his nEw Book.
A．DEmonstrAting thE prEvAlEnCE oF gAmBling
B．ExAmining thE BEnEFits AnD Costs oF gAmBling
C．Exploring thE CAusEs oF gAmBling
D．showing whEthEr thE BEnEFits oF gAmBling outwEigh its Costs