user
A man is 20 years old but has only had 5 birthdays.  How is that possible?
A: his birthday is leap year
B: hill
C: messenger
D: senior
E: he was born febuary 29th
assistant
<|begin_of_thought|>

Deep Thought is thinking for 7.5 million years.

<|end_of_thought|>

<|begin_of_solution|>

E

<|end_of_solution|>