Tereza Allen, the CEO of Allen Chemicals, invited executives from several other major chemical companies to a meeting. At the meeting, she encouraged them to lobby the Environmental Protection Agency as well as other government agencies to reduce the high standards for emissions that had just been announced. She and the group agreed that the money required to meet the new emission standards would put a real dent in their profits. Which of the following is true?

a$.$ This meeting and the executives are in violation of restraint of trade.

b$.$ By attending and agreeing with Allen, they are now in violation of trade by group boycott.

c$.$ The companies are now in violation of vertical trade restrictions.

d$.$ The agreement is not in violation of trade restraints.