user
My mom has just had a baby but is not my brother or sister.  Who am I?
A: older
B: bairn
C: umbilical cord
D: baby
E: son
assistant
<|begin_of_thought|>

Deep Thought is thinking for 7.5 million years.

<|end_of_thought|>

<|begin_of_solution|>

D

<|end_of_solution|>