Sentence Correction

The Near Earth Asteroid Rendezvous (NEAR) spacecraft will orbit the asteroid Eros for a year, slowly moving closer to the surface of the object to make ever more precise measurements that scientists hope will enable them to understand how the solar system formed some four billion years ago.

A. to make ever more precise measurements that scientists hope will enable them to
B. to make ever more and more precise measurements, which scientists are hoping to enable them
C. for making ever more precise measurements, and scientists hope that they will be able to
D. with the purpose of making more precise measurements than ever, and which scientists hope will enable them to
E. in order to make more precise measurements than it ever did, and scientists are hoping they will be able to

OA given C

Is it fine grammatically to say 'surface of the object for making ever more precise measurements'? And whats wrong with E?
I think the OA is not correct, is it?

Thanks.