The correct order of political parties in Mexico on a left/right continuum is PRD; PRI; PAN.
The correct order of political parties in Mexico on a left/right continuum is option C) PRD; PRI; PAN. 
The PRD (Party of the Democratic Revolution) is a left-wing party in Mexico, advocating for social justice and economic equality. The PRI (Institutional Revolutionary Party) is considered to be center-right, although it has gone through different ideological shifts throughout history. The PAN (National Action Party) is a right-wing party in Mexico, advocating for free markets and conservative values.
Learn more about Political parties in Mexico