It Is Only in the Past Few Years That Women

It is only in the past few years that women in the armed services of the United States have been permitted to be active combatants in a battlefield setting.While this has taken place over a number of years and has evolved for a variety of reasons,it is also reasonable to suggest that it has happened in part because of

A) increased militarization worldwide.
B) greater global threat levels.
C) increased terrorist activity.
D) a shortage of qualified male soldiers.