Pushing on a mass of 15 kg with a sideways force of 120 N is not enough to get the~mass to start sliding across the floor. Which of the following best describes the coefficient of static friction between the floor and the mass? 
选项为:A:$\mu\textbackslash{} =\textbackslash{} 0.8$  B:$\mu\textbackslash{} \gt\textbackslash{} 0.8$  C:$\mu\textbackslash{} \lt\textbackslash{} 0.8$  D:$\mu\textbackslash{} =\textbackslash{} 1.25$  请回答其中一个选项.