Could someone explain why the answer is C? What does attending a college of choice have anything to do with it?

http://classic.7sage.com/lsat_explanations/lsat-18-section-2-question-02/

Could anyone explain why the answer is C- All lawyers are cattle ranchers and not A- Some lawyers are cattle ranchers.

http://classic.7sage.com/lsat_explanations/lsat-25-section-2-question-19/

Can someone explain why the answer choice is B?

http://classic.7sage.com/lsat_explanations/lsat-26-section-2-question-09/

Can someone explain why the correct answer is B? Thank you!