The "Nongraded Program" of Between-Class Ability Grouping Is Best Described

The "nongraded program" of between-class ability grouping is best described as which of the following?

A) Classes in which student progress is not assessed and grades are not assigned
B) Classes in which students are grouped according to ability regardless of age or grade level
C) A philosophy of assessing students using descriptive evaluations rather than letter grades
D) A style of teaching in which students work independently to complete specific objectives