According to the path$-$goal theory, in which of the following cases would an achievement$-$oriented style be most appropriate?

a$.$ When group members have low morale due to dissatisfying, frustrating, or stressful tasks

b$.$ When leading team members who are working on ambiguous and nonrepetitive tasks

c$.$ When the degree of subordinate task structure is low

d$.$ When leading group members who are unsure of themselves