What is the optimal $($target$)$ service level that Erica should offer to maximize the expected profit?

Question $1$ options:

$0\mathrm{.}698$

$0\mathrm{.}752$

$0\mathrm{.}808$

$0\mathrm{.}908$

$0\mathrm{.}853$

$0\mathrm{.}793$