What is the language L$($r$)$ described by the following regular expression?r$=($b$+$c$)(\backslash$lambda $+$a$)($b$+$c$)(\backslash$lambda $+$a$)($b$+$c$)(\backslash$lambda $+$a$)($b$+$c$)?($a$)$ every string in L$($r$)$ has at least one a$($b$)$ every string in L$($r$)$ has at least two a$$s$($c$)$ every string in L$($r$)$ has at least three a$$s$($d$)$ none of the above