These top 100 SC questions are brutal - they take me longer to do than LSAT CR .... I didn't even spot the extra 'to' in D.
A and B suffer from a meaning issue. We want to convey the idea that the goals were established by the program. However, the way its written makes it seem as though the program 'figured out' that the main goals are such and such.
The Mars Exploration Program established that the main scientific goals of the MSL mission are to help determine whether or not Mars could ever have supported life, as well as determining the role of water, and to study the climate and geology of Mars.
A.
The Mars Exploration Program established that the main scientific goals of the MSL mission are to help determine whether or not Mars could ever have supported life, as well as determining the role of water, and to study the climate and geology of Mars.
B.
The Mars Exploration Program established that the main scientific goals of the MSL mission are to help determine whether Mars could ever have supported life, as well as to determine the role of water, and to study the climate and geology of Mars.
C. As established by the Mars Exploration Program, the main scientific goals of the MSL mission are to help determine whether Mars could ever have supported life, as well as determining the role of water, and to study the climate and geology of Mars.
D. As established by the Mars Exploration Program, the main scientific goals of the MSL mission are to help
to determine whether Mars could ever have supported life, as well as determining the role of water, and to study the climate and geology of Mars
E. As established by the Mars Exploration Program, the main scientific goals of the MSL mission
is to help determine whether Mars could ever have supported life, as well as determining the role of water, and to study the climate and geology of Mars.