<p>Having an exceptionally hardy and well-preserved physique, NASA officials chose 77-year-old John Glenn to participate in a study of the effects of space weightlessness on the human body.
A. Having an exceptionally hardy and well-preserved physique, NASA officials chose 77-year-old John Glenn
B. NASA officials who chose 77-year-old John Glenn for his exceptionally hardy and well-preserved physique
C. Based on his exceptionally hardy and well preserved physique, 77-year-old John Glenn was chosen by NASA officials
D. Because his physique was exceptionally hardy and well-preserved, NASA officials chose 77-year-old John Glenn
E. Having an exceptionally hardy and well-preserved physique, NASA officials therefore chose 77-year-old John Glenn</p>
<p>SEe now here is the dilemma. I put C as my answer and thought it was right. But the book said the answer was D. Its explanation was pointing toward C amnd I just wanted to see if the book had a mistake. I guess it did..</p>
<p>I thought it was D too.
Because C says "Based on his exceptionally hardy and well preserved physique, 77-year-old John Glenn was chosen by NASA officials chose 77-year-old John Glenn to participate in a study of the effects of space weightlessness on the human body."
I don't think it makes sense to put "based on" before the action. Also, he wasn't chosen BASED ON his physique, he was chosen BECAUSE OF IT. There is a difference between something that is based on and something that is BECAUSE of.</p>
<p>"Based on" suggests that it was partly because of a certain reason; "because of" tells us it was the exact reason why.
Sorry if I can't explain this extremely clearly, but "based on" sounds wrong to me.</p>
<p>D is good because it avoids the passive voice. "NASA officials chose John Glenn" is better than "John Glenn was chosen by NASA," although both are correct. They ask you to choose the BEST answer, and it is always best to avoid passive voice.</p>