To avoid unionization, supervisor $\sqrt[\phantom{2}]{3}$ should avoid doing ALL of these, EXCEPT:

Multiple Choice

threatening employees with harsher terms and conditions of employment if they engage in union activity.

interrogating employees about pro$-$union or anti$-$union sentiments$.$

promising employees that they will receive favourable terms of employment if they forgo unionization.

spying on employees known to be or suspected of being engaged in pro$-$union activities.

providing a valuable package of wages and benefits.