<u>Statement Reason </u>
AB║CD , AD║CB Given
m∠BAC = m∠ACD Alternate Interior Angles
m∠ACB = m∠CAD Alternate Interior Angles
AC = AC Reflexive Property of Equality
ΔABC ≅ΔCDA ASA ≅
I believe your answer is going to be increasing linear. If it's doubling constantly then it's increasing so that takes out 2 options. And since it's constant, it isn't exponential, therefore you only have increasing linear left.
I hope I was able to help. Best of luck.