A piece of pasture can feed $$17$$ cow for $$30$$ days or $$19$$ cows for $$24$$ days. If the grass grows at the same speed every day, how many cows can it feed for $$6$$ days? ． 
选项为:A:$$38$$  B:$$45$$  C:$$49$$  D:$$52$$  请回答其中一个选项.