I think the answer is letter B
Answer:
Angle ABC is bisected by BD
BC =Half AC
2 mangle DBC =mangle ABC
ANSWER

EXPLANATION
To find a positive angle that is coterminal with

We add multiples of 2π until we get a positive angle that is less than one revolution,
We add to obtain,

This simplifies to,

This is the first positive angle that is coterminal with

and is less than one revolution.
It is 50 thousands because 5 times 10 = 50.