aditya8062 wrote:Active underwater faults are observed carefully, tectonophysicists monitor the physical processes that underlie tectonic formation to predict the movements of the Earth's crust.

A. carefully, tectonophysicists monitor the physical processes that underlie tectonic formation to predict the movements of the Earth's crust

B. carefully, whereas tectonophysicists monitor the physical processes that underlie tectonic formation to predict the Earth's crust's movements

C. carefully; the physical processes that underlie tectonic formation are monitored by tectonophysicists so that they can predict the movements of the Earth's crust

D. carefully; tectonophysicists monitor the physical processes that underlie tectonic formation to predict the movements of the Earth's crust

E. by tectonophysicists who carefully monitor the physical processes that underlie tectonic formation to predict when the movement of the Earth's crust occurs

my doubt: i am not finding any solid reason to eliminate C . i feel that "they" can very well refer to "tectonophysicists" .

thanks

Hi Aditya, Rich is also an expert and has been doing a great job at helping us.

I believe what he intends to say is that everything else remaining the same, active voice should be preferred.

For example, in OE for option D for question 16 in OG-13: there is no reason to use passive voice.