Professor Wang Is Interested in Looking at the Grandparent -

Professor Wang is interested in looking at the grandparent - grandchild relationship.Wang wonders whether grandparents assume different roles when providing care to grandchildren.That is,are some grandparents very distant from the grandchildren while others become surrogate parents? According to the Lofland's scheme,Wang is focusing on:

A) Frequencies
B) Causes
C) Processes
D) Structures
E) Magnitudes