PROOF: Given isosceles ΔABC with AB ≌BC, I can construct BD, the angle bisector of ∠B. Then, by the definition of an angle bisector, I know that ∠ABD ≌ ∠CBD. I also know that line segments are congruent to themselves, so BD ≌ BD by the reflexive property of congruence. I now have two pairs of sides and an included angle that are congruent, so I know that ΔABD ≌ ΔCBD by the SAS Congruence Theorem

Question

Which statement should be placed at the end of the proof?

finally, corresponding parts of congruent triangles are congruent by the CPCTC theorem, so ∠A ≌ ∠B.
finally, corresponding parts of congruent triangles are congruent by the CPCTC theorem, so ∠A ≌ ∠C.
finally, ∠A ≌ ∠C by the Base angles theorem.
finally, corresponding parts of congruent triangles are congruent by the CPCTC theorem, so AB ≌ BC

Answer 1

The most appropriate statement to place at the end of your proof is:

finally, corresponding parts of congruent triangles are congruent by the CPCTC theorem, so ∠A ≌ ∠C.

This follows logically from your earlier conclusion, as you established that ΔABD ≌ ΔCBD. Since corresponding parts of congruent triangles are congruent (CPCTC), it directly leads to the conclusion that ∠A ≌ ∠C, which is consistent with the properties of isosceles triangles.