Answer:
D. If and , then is an example of transitive property of congruence.
Step-by-step explanation:
Transitive property of congruenc: If one segment is congruent to second segment and second is congruent to third segment then the segment one is congruent to third segment.
For example: If
and 
Then 
Therefore we can see in angles
If 
And 
Then 
Therefore, the statement of transitive property written as
If and, then
Hence, If and, then is an example of the transitive property of congruence.