Though expensive,a sofa made of genuine leather lasts longer than _____made of artificial leather

Though expensive,a sofa made of genuine leather lasts longer than _____made of artificial leather
A.it B.those C.one D.that
为什么选C呢?
The information on the Internet gets around much more rapidly than ______ in the newspaper.
A．it B．those C．one D.that
为什么这道题选D，这两道题的区别是什么呢？