B is 12
c is 6 because you don't count the zero
Given:

To find:
The
.
Solution:
In circle B,
is central angle and
is inscribed angle from two points A and C.
According to central angle theorem, central angle is always twice of inscribed angle.
[Central angle theorem]

Divide both sides by 2.


Therefore,
.
Answer:
B:subtraction property
Step-by-step explanation: