Which oft he following regular expressions describe the language over the alphabet $\{$a$,$b$\}$ that consists of all strings that begin and end with the same letter.

a$)$ ab$*$a$+$ba$*$b

b$)$ a$($b$*$a$)*+$b$($a$*$b$)*$

c$)$ ab$*$a$*$b$*$a$+$ba$*$b$*$a$*$b d$)$ none of the above