A bubble sort requires at most $\_\_\_\_\_\_\_\_\_$ passes to sort an array of $\backslash ($ n $\backslash )$ items.

Question $7$ options:

$\backslash ($ n$-1\backslash )$

$\backslash ($ n$-2\backslash )$

$\backslash ($ n $\backslash )$

$\backslash ($ n$/2\backslash )$