Industry$-$wide collective agreement bargaining in the construction industry, in general, results in a compression of wage differentials among the various trades. In general, most of today$$s collective bargaining sessions involve re$-$negotiation of an expiring collective agreement. Which of the following is not correct about construction collective agreement in Quebec, as per Act R$-20$An Act respecting labour relations, vocational training and workforce management in the construction industry$$:

a$.$

To be applicable in a sector, a collective agreement must be ratified by the contractor party and at least three union associations representing more than $50\%$ of the industry$$ workers.

b$.$

Negotiations take place at the provincial and municipal levels for all construction workers and contractors and the conditions agreed between the parties are applicable to the entire industry throughout the province.

c$.$

The current collective agreements are in effect until $30$ April $2025$ with working conditions continue to apply until there is an agreement in principle, strike or lockout in the sector concerned.

d$.$

The labour relations regime for the construction industry defines four sectors for the purposes of negotiating collective agreements for $2021-2025$ with common clauses.