Read the chapter's mini case, and then answer the question.

chapter's mini case

In addition to sexual harassment concerns, multinational corporations must also consider other ethical concerns such as the abuse of workers in other countries where they operate or outsource around the world. To this end, global labor standards minimally involving prohibitions against slave or forced labor, restrictions on the use of child labor, certain basic job safety protections, and the right of workers to form labor unions, have been through which of the following?

a$.$ Civil Rights Act of $1964$

b$.$ United Nations International Labor Organization $($ILO$)$

c$.$ North American Free Trade Agreement $($NAFTA$)$

d$.$ North American Agreement on Labor Cooperation $($NAALC$)$