Implied volatility and realized volatility

Which comes first, the option's price or its implied volatility?

• The price; IV is solved from it
• The IV; the exchange sets it and the price follows
• Neither; both are copied from realized volatility

A 30-day BTC option shows an IV of 50%. What does that mean?

• BTC is expected to move 50% in the next 30 days
• The option is priced as if BTC's returns had a 50% standard deviation per year
• BTC moved 50% over the past year