(a) An act, done with specific intent to commit an offense under this chapter, amounting to more than mere preparation and tending, even though failing, to effect its commission, is an attempt to commit that offense.

(b) Any person subject to this chapter who attempts to commit any offense punishable by this chapter shall be punished as a court-martial may direct, unless otherwise specifically prescribed.

(c) Any person subject to this chapter may be convicted of an attempt to commit an offense although it appears on the trial that the offense was consummated.