When did barack obama become president

Which of the following was a difficulty faced by the ottoman empire in the 1700s and 1800s?   a.  financial independence      b.  lack of trained artisans      c.  refusal to trade with other nations      d.  rebelling ethnic groups

Don’t mind the already marked answer but taking it now

3. according to oliver, how can the fast food industry with the food revolution? i will give brainliest