[tex]-67\geq5+3n-21\\\\-67\geq3n+(5-21)\\\\-67\geq3n-16\ \ \ \ |+16\\\\-51\geq3n\ \ \ \ |:3\\\\-17\geq n\to n\leq-17\\\\Answer:\ \boxed{B.\ n\leq-17}[/tex]
