The $80/20$ principle:

Multiple Choice

is a territorial management concept that favors a salesperson putting $80$ percent of her time on action and $20$ percent on planning.

is a territorial management concept that favors a salesperson putting $80$ percent of his time on planning and $20$ percent on action.

refers to the fact that eighty salespeople require twenty sales managers to keep the appropriate $1-$to$-4$ ratio of supervisors to employees.

refers to the idea that $20$ percent of a firm's customers account for $80$ percent of a firm's profitability.

$$ indicates that no matter how hard a salesperson tries, $80$ percent of the customer's potential business ends up going to competitors.