I'll give you a question, please answer with step-by-step reasoning process.
What would cause someone to gain weight and be goingto bed early?\nOptions:\n- drowsiness\n- sleeping in\n- insomnia\n- exercise\n- pregnancy

pregnancy
Pregnancy means the condition of being pregnant.

Being pregnant means carrying a baby in one's womb.

Carrying a baby in one's womb makes them gain weight.

Carrying a baby in one's womb makes them go to bed early.

.

So, the final answer is pregnancy