Which of the following is true of executive orders $11246,11375,$ and $11478?$

a$.$ They require public and private employers to conduct due diligence as soon as a business deal is closed.

b$.$ They require state governments and federal contractors to prevent the use of summary dismissal in organizations.

c$.$ They require all educational institutions and private organizations with $10$ or more employees to follow the regulations established by the Equal Employment Opportunity Act of $1972.$

d$.$ They require federal contractors to take affirmative action to compensate for historical discrimination against women, minorities, and individuals with disabilities.