Which of the following condition ensures that the size of liabilities matches the position in bonds in the construction of the immunized portfolio:

a.

Macaulay duration of the stream of liabilities must be equal to Macaulay duration of bonds used

b.

nominal value of bonds must be equal to the nominal value of liabilities

c.

present value of bonds must be equal to present value of liabilities

d.

present value of bonds must be equal to the nominal value of liabilities