Effective Radiation Protection Practices Include All of the Following Except

Multiple Choice

Effective radiation protection practices include all of the following except
1) effective communication and immobilization devices.
2) maintaining minimum source to skin distances (SSD) .
3) oscillating grids and contact shields.
4) collimation and minimizing technical factors.

A) 1 only
B) 1 and 2 only
C) 1, 2, and 3 only
D) 1, 2, and 4 only