题目内容：

Now every family in Harbin uses natural gas.(天然气) But the price of it  will be higher in May,. If each month Jin’s family uses the same units of natural gas, they will spend _____more IN THIS YEAR.

The Price of Natural Gas for Our Life
Used to be:  ￥ 2.00 / unit	From May 1, : ￥ 2.80 / unit
Total (used to be in each month)￥ 30	Total (in each month from May):￥ ?

A. ￥ 12                 B. ￥ 144               C. ￥96