A triangle with an acute angle of 30 degrees is within a circle, which forms the shaded region. Find the area of the shaded region. 
Choices:
A:35.2
B:43.2
C:53.5
D:56.9
Please directly answer the question and provide the correct option letter, e.g., A, B, C, D.
Question: A triangle with an acute angle of 30 degrees is within a circle, which forms the shaded region. Find the area of the shaded region. 
Choices:
A:35.2
B:43.2
C:53.5
D:56.9
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: A triangle with an acute angle of 30 degrees is within a circle, which forms the shaded region. Find the area of the shaded region. 
Choices:
A:35.2
B:43.2
C:53.5
D:56.9