For What Reason Was the 1970 District of Columbia Preventive

For what reason was the 1970 District of Columbia preventive detention law rarely used?

A) it was found to be unconstitutional within the first year that it was implemented
B) federal prosecutors chose not to use it and continued setting high bail for defendants they wanted to detain
C) bleeding heart judges continued to release defendants without prosecuting and punishing them
D) it was actually used extensively and resulted in a major increase in our nation's prison population