The leverage requirement stipulated in Basel $3$ and Basel $4$:

options:

$1)$ Calculates minimum capital ratio in terms of required capital divided by risky assets

$2)$ Calculates minimum debt ratio in terms of required capital divided by retained earnings

$3)$ Calculates maximum deposits that a bank can accept given the size of its loans

$4)$ Calculates maximum capital ratio in terms of required equity divided by debt