Which of the following investments has the highest effective annual return $($EAR$)?$

$($Assume that all CDs are of equal risk.$)$

a$)$ a bank $CD$ that pays $7\mathrm{.}00$ percent interest compounded daily

b$)$ a bank $CD$ that pays $7\mathrm{.}10$ percent compounded monthly

c$)$ a bank $CD$ that pays $7\mathrm{.}30$ percent annually

d$)$ a bank $CD$ that pays $7\mathrm{.}25$ percent compounded semiannually