1 . Consider strings of length $57$, in which each character is one of the characters $a,b,c,d,e$. How many such strings have exactly $19$ letters $e$?
(a)
$\binom{57}{5}\cdot 4^{38}$
(b)
$\binom{57}{19}\cdot 4^{38}$
(c)
$\binom{57}{19}\cdot 5^{38}$
(d)
$\binom{57}{5}\cdot 5^{38}$
(e)
$5^{19}\cdot 4^{38}$