If a for-profit firm that has paid out record bonuses to its executive every year while underfunding contributions to unionized workers' pensions required under the collective agreement then attempts to reduce workers' pension entitlements, the union members will most likely .
a) be unable to defend against this action.
b) take defensive strike action.
c) enter into collective bargaining
d) receive higher wages instead

B. Take defensive strike action.

Explanation:

One of the functions of a trade union or labor union is to protect the interest of its members in a workplace. So, if a profit firm treats its workers poorly by underfunding contribution to workers pension as required under a collective agreement while paying out record bonuses to executives then attempts attempt to reduce workers pension entitlements, the union members will most likely embark on an industrial strike.

The aim of the strike is to halt daily operations of the firm until their demands are heard and an agreement is reached. The members of the union were treated unfairly by the firm by not honoring their pension funding agreement and to make matters worse the decided to try and reduce the workers pension.

If the members don't embark on the industrial strike, the firm would reduce their pension benefits. The most likely action of the union members would be to embark on a defensive strike action to protect themselves.

whats the

b. take periodic breaks and alternate between tasks.  

will increase work efficiency, and avoid health issues.