Why do you use parameter mapping in a calculation view? Note: There are 2 correct answers to this question.

Why do you use parameter mapping in a calculation view? Note: There are 2 correct answers to this question.
A . To convert the data types of input parameters
B. To assign variables to one or more attributes
C. To push down filters to the lowest level calculation views
D. To pass variable values to external value help views

Answer: C,D