These are european-style options and as such they can only be exercised on maturity/expiration.
The market data used in the contest are historical numbers. You will need to predict the option value based on one-year forward expiration. Your calculated option fair value, and thus your investment choice, will be compared with our historical "one-year
forward" price of the underlying to determine your *expected* PnL.
There is no re-investments required.