At a factory, the cost of making different numbers of toothbrushes is shown in the table below.




A linear function models the cost based on the number of toothbrushes made. Which statement about the rate of change of this function is true?


The cost increases by $1.50 for each additional toothbrush made.
The cost increases by $1.50 for each additional toothbrush made.

The cost increases by $4.50 for each additional toothbrush made.
The cost increases by $4.50 for each additional toothbrush made.

The cost increases by $9.00 for each additional 3 toothbrushes made.
The cost increases by $9.00 for each additional 3 toothbrushes made.

The cost increases by $18.00 for each additional 3 toothbrushes made.