I don't mean to be flippant but there is no nice way to kill somebody in a war.

Answer: Option A

Frivolous : not having any serious purpose or value.
Mean : intend to convey or refer to (a particular thing); signify.
Desperate : feeling or showing a hopeless sense that a situation is so bad as to be impossible to deal with.
Naughty : (especially of a child) badly behaved; disobedient.
Flippant : not showing a serious or respectful attitude.

Synonym of Flippant is Frivolous