There were so many furs that when they were packed tightly a

There were so many furs that when they were packed tightly and tied together they made a bundle almost as big as Pa.a、lightly
a、lightly
b、 firmly
c、 together
d、 in a bundle
替换“tightly”这题应该选哪个?为什么?
有没有其他具有说服力的答案 清翻译整句