The languages below are not regular. For each, (a) what string would you pump, and (b) how does pumping that string show the language is not regular?

a. L = {www | w ? {a, b}*}

b. L = {anba2n | n >= 0}

c. L = {anbm| 0<= n <= m }

d. L = {anbm | n >= m >= 0}

e. L = {w??* | w contains more as than bs}