B: internal stable; internal unstable

    Correct.

An example of an internal stable attribution regarding the cause of academic failure would be lack of ability or lack of personal discipline.  An internal unstable attribution of academic failure is attributing your poor performance to factors such as lack of effort, or lack of interest in the subject.  In attributional retraining, students ARE encouraged to cease attributing failure to lack of ability (internal stable) and instead attribute failure to lack of effort (internal unstable).  This way, as student feels that if he can change his poor habits or skills or amount of effort or practice (internal unstable), he can improve his grades.