Answer:
First is direct second is non direct
Angle = 68⁰ is an inscribed angles, this angle equal 68⁰,
so it intersect arc = 2*68⁰= 136⁰.
Arc of the whole circle (circumference) =360⁰,and it also =b+104+136.
b+104+136 =360
b=360-(104+136) = 120⁰
Answer A. b=120⁰.
It is given in the question that B is in between C and D.
Therefore

Substituting the given values of CB,BD and CD, we will get

Combining like terms, we will get

Now we need to move 4 to the right side by adding 4 to both sides, that is
