There are four rays B A, B D, B F, and B C with a shared starting point B. \overrightarrow B A and \overrightarrow B C are opposite rays and \overrightarrow B D bisects \angle A B F. If m \angle F B C = 2 x + 25 and m \angle A B F = 10 x - 1, find m \angle D B F.
Choices:
A:25.5
B:50
C:54
D:64.5
Please directly answer the question and provide the correct option letter, e.g., A, B, C, D.
Question: There are four rays B A, B D, B F, and B C with a shared starting point B. \overrightarrow B A and \overrightarrow B C are opposite rays and \overrightarrow B D bisects \angle A B F. If m \angle F B C = 2 x + 25 and m \angle A B F = 10 x - 1, find m \angle D B F.
Choices:
A:25.5
B:50
C:54
D:64.5
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: There are four rays B A, B D, B F, and B C with a shared starting point B. \overrightarrow B A and \overrightarrow B C are opposite rays and \overrightarrow B D bisects \angle A B F. If m \angle F B C = 2 x + 25 and m \angle A B F = 10 x - 1, find m \angle D B F.
Choices:
A:25.5
B:50
C:54
D:64.5