单选题：根据 下列材料，回答题Rowena and Billy Wrangler are model high school

根据 下列材料，回答题
Rowena and Billy Wrangler are model high school students．They study hard and do extremely well on achievement tests．And next year，Rowena will be attending Harvard Uniyersity．Billy，her younger brother.hopes to go to Comell．what makes Rowena and Billy different from most students is that they don’t go to school．In fact，they’ve never been to school．Since kindergarten，they’ve studied at home．Neither Rowena nor Billy feels as if they've missed out on anything by being taught at home．Like many of more than one million people who receive home schooling in the United States，they feel as if they’ve gorten a good education．
The home—schooling trend began in the U．S．in the 1980s with parents keeping their children out of public schools so they could provide religious education at home．Today，as the home—schooling trend continues to grow．parents are more likely to consider home schooling as all option because they believe schools don’t do a very good job of teaching and ale occasionally dangerous places．But Can parents really do a better job?’
The answer in many cases is yes．In many studies，students taught at home ranked average or above average when compared to students who went to public schools．More importantly，these students were often more self-directed and have a greater depth of knowledge．“They ale very well prepared for academic challenges，”says Patficia Riordan，the dean of admissions at George Mason University．
One such student，Robert Conrad，now a sophomore at university，claims he really learned how to study and schedule his time during his eight years of home schoolin9．Still，not every student is as successful as Robert．
“For every home—schooling success story，there are an equal number of failures，’’states Henry Lipscomb，an educational researcher．“There are just SO many disadvantages that students mught at home have to overcome．”For example，they have fewer chances to interact with others of their own age．Consequently，they sometimes lack the usual social skills．“No matter what，though，”states Lipscomb．“home．schooling is a growing trend．I think we’11 be seeing more and mole of this．

Compared with other students。吐le most different thing Rowena and Billy do is that———— A．they study hard
B．they do extremely well on achievement tests
C．they never go to school
D．they feel they have gotten a good education