In quadrilateral ABCD, the diagonals intersect at point T. Thomas has used the Alternate Interior Angles Theorem to show that angle ADB is congruent to angle DBC and that angle DBA is congruent to angle BDC. Which of the following can Thomas use to prove that side AB is equal to side DC?

AC ≅ AC
AC ≅ DB
TA ≅ TC
DB ≅ DB