What effect does the issuance of a $2-$for$-1$ stock split have on each of the following?

Par Value Shares $-$ No effect $|$ Retained Earnings $-$ No effect

Par Value Shares $-$ Decrease $|$ Retained Earnings $-$ Decrease

Par Value Shares $-$ Decrease $|$ Retained Earnings $-$ No effect

Par Value Shares $-$ Increase $|$ Retained Earnings $-$ No effect