Which One of the Following Statements Best Illustrates Prior Knowledge

Which one of the following statements best illustrates prior knowledge activation in a geometry lesson?

A) "Today we will be studying three different kinds of triangles: acute, right, and obtuse."
B) "Calculating the volume of a sphere is similar to a procedure you learned last month-calculating the area of a circle."
C) "Okay, class, it's time to put your reading assignment away so that we can begin today's geometry lesson."
D) "Do you know how many square feet you have in your bedroom? After learning how to calculate the area of a rectangle today, you will know how to figure out exactly how big your bedroom is."