In the figure above, triangle ABC is inscribed in the circle with center O and diameter AC. If AB = AO, what is the degree measure of angle ABO?
Choices:
A.15*\degree
B.30*\degree
C.45*\degree
D.60*\degree
E.90*\degree
Please directly answer the question and provide the correct option letter, e.g., A, B, C, D.
Question: In the figure above, triangle ABC is inscribed in the circle with center O and diameter AC. If AB = AO, what is the degree measure of angle ABO?
Choices:
A.15*\degree
B.30*\degree
C.45*\degree
D.60*\degree
E.90*\degree
Please first conduct reasoning, and then answer the question and provide the correct option letter, e.g., A, B, C, D, at the end.
Question: In the figure above, triangle ABC is inscribed in the circle with center O and diameter AC. If AB = AO, what is the degree measure of angle ABO?
Choices:
A.15*\degree
B.30*\degree
C.45*\degree
D.60*\degree
E.90*\degree