In the right triangle, an acute angle is labeled as \angle 4 with an external angle of 123 degrees. Find m \angle 4.
Choices:
A:33
B:43
C:57
D:123
Please directly answer the question and provide the correct option letter, e.g., A, B, C, D.
Question: In the right triangle, an acute angle is labeled as \angle 4 with an external angle of 123 degrees. Find m \angle 4.
Choices:
A:33
B:43
C:57
D:123
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 right triangle, an acute angle is labeled as \angle 4 with an external angle of 123 degrees. Find m \angle 4.
Choices:
A:33
B:43
C:57
D:123