The second option is definitely more complicated
The third excerpt is structured correctly.
1. C. The work was difficult, yet Lucy was glad to have a job.
2. C. Folks were struggling to survive in most places, but in California they had jobs.
3. B. Dos Palos was a small community, but the land was good for farming.
I'm fairly certain of all these answers!
Hope this helps :)
I think the correct answer is sentenced 7