In practice, it is more important to focus on identifying and treating alcoholism rather than ...

In practice, it is more important to focus on identifying and treating
  alcoholism rather than underlying causes because ________.
 
  A. the exact etiology of alcoholism is known and makes clear that
  treatment of alcoholism is a primary issue
  B. secondary diagnosis has no significance in the treatment of
  alcoholism
  C. even when underlying causes are known, they become problems
  to be solved in their own right in addition to arresting the
  alcoholism
  D. resolving mental disorders that precipitate alcoholism will resolve
  the alcoholism