(a) It is an affirmative defense to a prosecution that the actor engaged in the conduct charged to constitute an offense because the actor reasonably believed he or she was compelled to engage in the conduct by the threat or use of unlawful force against the actor's person or the person of another that a person of ordinary firmness in the actor's situation would not have resisted.(b) The affirmative defense provided by this section is unavailable if the actor recklessly placed himself or herself in a situation in which it was reasonably foreseeable that the actor would be subjected to the force or threatened force described in subsection (a) of this section.Acts 1975, No. 280, § 208; A.S.A. 1947, § 41-208.