My mom remembers the days when phones had cords. which is the adjective clause in the folllowing sentence? a=when phones had cords b=remembers the days c= had cords d=my mom remembers the days

Which sentence is punctuated correctly? the shoes normally cost 40 dollars, however; we got them on sale. the shoes normally cost 40 dollars however we got them on sale. the shoes normally cost 40 dollars, however, we got them on sale. the shoes normally cost 40 dollars; however, we got them on sale.