答案:A
解析:
In the question, you are told that 7 gallons of gasoline can plow 3 acres and you are asked to find how many acres, call it x, can be plowed by 16 gallons. You can set up a ratio of the number of gallons of gasoline used to the number of acres plowed. Therefore, you have 7/3 = 16/x. Cross-multiplying and solving for x gives you the answer of x = 48/7 acres, or 6 and (6/7) acres.