Indicate Whether in the Following Examples the IV Is Necessary

Indicate whether in the following examples the IV is necessary, sufficient, both, or neither.
a. The willingness to change is a _____________ cause of desistance.
b. Driving under the influence of alcohol is a ______________ cause for arrest.
c. Being born in the United States is a ________________ cause for U.S. citizenship.
d. Being convicted for an offense is a ___________________ cause for a criminal record.