Appropriate Scatter Radiation Control Methods Include Which of the Following

Appropriate scatter radiation control methods include which of the following?
1) Tight collimation
2) Lead masking at the edge of the exposure field
3) Appropriate use of a grid
4) Lower kV settings
5) Using an air gap method

A) 1, 2, and 4 only
B) 2, 3, and 5 only
C) 1, 2, 3, and 4 only
D) 1, 2, 3, 4, and 5