Arecipe asks that the following three ingredients be mixed together as follows: add 1/2 of a teaspoon of baking soda, and every 1/4 of a teaspoon of salt. which of the following rates is a unit rate equivalent to the ratios shown above?

a. 1 teaspoon of baking soda per 2 teaspoons of salt
b. 1/2 teaspoon of salt per 1 teaspoon of baking soda
c. 2 teaspoons of salt per 1 teaspoon of baking soda
d. 2 teaspoons of salt per 1 cup of flour