Which of the Following Is True About Sweetbreads

Which of the following is true about sweetbreads?

A) They are relatively inexpensive.
B) They are found in mature cattle, but not in calves.
C) They should be soaked and blanched before they are cooked.
D) They tend to be strong in flavor and tough in texture, so they must be cooked for much longer times in order to weaken their flavor and break down their connective tissues.