Suppose you have $7$ events $-$ A$,$ B$,$ C$,$ D$,$ E$,$ F$,$ and G$.$ How many pairwise comparisons would you need to do to complete a pairwise ranking matrix?

Group of answer choices

$7^2=49$

$(7)(7-1)/2=21$

$7!(=7$ x $6$ x $5$ x $4$ x $3$ x $2$ x $1)$

$7$