1.  Also, to make the argument more convincing the vice-president should provide more information concerning employees' quality and consider the other possible factors which will effects the profit.

2.  To make the argument more convincing the author should provide more information concerning employees' quality and consider the other possible factors which will effects the profit.

3.  To make the argument more convincing the arguer should provide more information concerning employees' quality and consider the other possible factors which will effects the profit.