When a manager decides to increase the in$-$stock target from $90\%$ to $99\%,$ s$/$he implicitly assumes that... $...$fill rates are too high and should be lowered.

$...$order placement costs are too high and should be lowered.

$...$cycle stock holding costs are too high and should be lowered.

$...$stockout quantities are too high and should be lowered.

All of the statements listed here are correct.