Which is of the following is correct? 

a. When tax shield on debt is exactly offset by higher personal taxes paid on interest income, there is no tax value gain from leverage. 

b. When personal tax rate on earnings is same as personal tax rate on debt, there is no tax value gain from leverage. 

c. Value gain from leverage decreases as (personal tax rate on debt - personal tax rate on earnings) increases. 

d. a and b. 

e. a and c.