Which of the following statements are true about early option exercise (for American style options)? (Assume r > 0)?

1. It is never optimal to early exercise a call option on a non-dividend paying stock.
2. It is never optimal to early a put option on a non-dividend paying stock.
3. It is always optimal to early exercise an in the money American style option on the day before a dividend is payable.
4. Because of possibility of early exercise, put call parity does not apply to American style options.