The garbage-can model is effective in which of the following situation/s? I. When managers have no specific goal preferences. II. When the means of achieving goals are unclear. III. When there are frequent changes in the participants involved in decision-making. IV. When the degree to which decision-makers can determine optimal decisions is limited by the individuals capacity and intelligence. (a) Only (IV) above (b) Both (I) and (II) above (c) Both (III) and (IV) above (d) (I), (II) and (III) above (e) All (I), (II), (III) and (IV) above.