Hi there!
The answer is segunda.
Ella es la segunda persona.
Answer: El/ella
Explanation: hope this helps!!
Answer:
The "personal a" is not necessary in that sentence. If you say: "No recuerdo tu nombre" it means "I don't remember your name". If you say "No recuerdo a tu nombre" it is not grammatically correct.
Given that including the "personal a" is grammatically incorrect, then the personal "a" is not necessary.