Context free languages

Are the following languages context-free or not? If yes, specify a context- free grammar in BNF notation that generates the language. If not, give ar informal argument (a) { a"bnc" I m > n 0, o > 0), with alphabet = {a, b, c} (b) { anbar, I n2 0 }, with alphabet = {a, b} (c) { wwR I w E . and wR (d) { a"b"cm,d" | n > 0, m > 0 }, with alphabet = {a, b, c, d} (e) { w | w has no more than 5 symbols), with alphabet ={a, b} iswin reverse }, with alphabet ={a, b)