What Statement Is True About Adding and Subtracting with Unlike

Multiple Choice

What statement is true about adding and subtracting with unlike denominators?

A) Should be introduced at first with tasks that require both fractions to be changed.
B) Is sometimes possible for students,especially if they have a good conceptual understanding of the relationships between certain fractional parts and a visual tool,such as a number line.
C) Is a concept understood especially well by students if the teacher compares different denominators to "apples and oranges."
D) Should initially be introduced without a model or drawing.