A nurse is reinforcing teaching about the purpose of the HbA1c test with an adolescent who has type 1 diabetes mellitus. Which of the following statements by the adolescent indicates an understanding of the teaching?

"This test checks for ketones in my urine."

"This test measures the amount of hemoglobin in my blood."

"This test tells me how much oxygen my body is carrying."

"This test checks my blood sugar over the last few months.”