The given blank can be filled with Plain.
The bagel is a round bread, which is made up of refined flour. The refined flour is less nutritious than the whole grain flour. The whole grain flour is used to make the whole grain bagel. Hence, the plain bagel is less nutritious than the whole grain bagel. The doughnut is made of plain bread, which is deep fried with sugar and cheese, which makes it less healthier than the plain bagel. Hence, the plain bagel is more nutritious than doughnut.