There are multiple problems with your question.
Example: $1,000 cash balance. 1 call option at a strike price of $200. New price is $240. Cash needed to exercise the option: $2,000
If you own a call with a $200 strike price, if you exercise it, you will need $20k for full payment share purchase, not $2k (or $10k on Reg T 50% margin).
Short sell 100 shares at $240 and use the cash to cover the call option exercise price.
Reg T margin for shorting effectively requires 50% of the value of the short sale. Half of $24k is a $12k initial margin requirement. You only have $1k of cash. Shorting the shares? Not gonna happen.
OR Purchase a put at a $240 strike price and let both exercise at expiration tomorrow.
What if your stock is above $240 at expiration and your $240 put expires worthless? You still have the problem of an assigned $200 call. And if expiration is between the strikes, your broker may consider this free riding. Call your broker to ascertain their expiration policy.
Brokers handle this situation in different ways. Some brokers will preemptively close such positions before expiration in order to avoid such complications. This isn't good because deep ITM options usually have very wide bid/ask spreads and the broker isn't going to work the order for a better price.
Your best solution? Sell to close your options before the broker's cut off time (usually 3:30 PM) if you're at such a broker and certainly by 4 PM expiration if not, in order to avoid free riding complications.
