Which one of these formulas correctly defines an effective annual rate $($EAR$)$ for any compounding period?

Multiple choice question.

EAR $=(1+$ Rate per period$)$Number of periods per year $-1.$

EAR $=$ Rate per period $\backslash$times Number of periods per year

EAR $=(1+$ APR$)$Number of periods per year $-1$

EAR $=$ Rate per periodNumber of periods per year