Since her firm$$s sales have increased from $3\mathrm{.}5$ to $4$ percent, Tanya has determined she would set her share of communication expenses at $4$ percent of sales, which is an example of the use of the $\_\_\_\_\_\_\_\_$ method.

Multiple Choice

competitive parity

objective$-$and$-$task

percentage of sales

rule$-$of$-$thumb

objective