Exchange lists are beneficial to creating a diet for diabetics because they
a. diabetics produce insulin.
b. create portion controls.
c. give diabetics freedom of choice in the foods they can eat.
d. make it easy to lose weight.

The question says,'exchange lists are beneficial to creating a diet for diabetic because theyThe correct option is C. Exchange lists group similar food together, the list show the number of food options that are available to diabetics and from which they can freely choose from during meals.

Iwould put 'think' in the blank

Blood transfusions were rarely done and often fatal; they were outlawed until the nineteenth century.