Ok so here it is:
-67 ≥ 5 + 3n -21
-67+ 21 ≥ 5 + 3n -21 + 21
the 21 cancel each other out
now add -67 and 21
-46 ≥ 5 + 3n
-46 -5 ≥ 5 -5 +3n
the 5 cancel each other out
now subtract -5 from -46
-51 ≥ 3n
-51 / 3 ≥ 3n / 3
3 cancel each other out
now divide -51 and 3
n ≤ -17
B