Which is correct? after the customers ate; the leftover food was thrown away or after the customers ate, the leftover food was thrown away

After the customers ate, the leftover food was thrown away       
is the right answer 

The correct answer would be B) or the second option ''After the customers ate, the leftover food was thrown away''. That sentence is correctly punctuated with the comma, because if you honestly read it out loud it makes sense with the comma rather than the semicolon so therefore its B).

Ithink that story needs some revising. hmm some academic language perhaps? and sylvia is but i do think that rainbow is spectacular