1 . Consider strings of length $67$, in which each character is one of the characters $a,b,c,d,e$. How many such strings have exactly $14$ letters $e$?
(a)
$\binom{67}{5}\cdot 4^{53}$
(b)
$\binom{67}{14}\cdot 4^{53}$
(c)
$5^{14}\cdot 4^{53}$
(d)
$\binom{67}{14}\cdot 5^{53}$
(e)
$\binom{67}{5}\cdot 5^{53}$