$7.$ Let L be a regular language over $($a$,$ b$,$ c$).$ Show that each of the following sets is regular. a$)\{?$ W E L and u$,$ ends with aa$)$ b$)($w we L or w contains an a$)$ c$)\{$ w L and w does not contain an a$\}$ d$)\{11$ Ulue Land u L$\}$