A Reason Workers Tend to Receive Fewer Promotions Than in the Past

A reason workers tend to receive fewer promotions than in the past is that:

A) most firms now believe hiring people outside the organization is a better way to fill management positions because it brings in "new blood."
B) the movement toward flatter organizational structures,provide fewer opportunities to move upward.
C) firms have found that promoting employees can create jealousy and resentment among the workers who are not promoted.
D) very few of today's supervisors and lower-level managers have the qualifications needed to move into higher management positions.