Use the following information to answer questions a & b.

Stanbic Fixed Income Securities Kefasi Mashanda is a portfolio manager at Stanbic Fixed Income Securities (SFIS), which has entered into a contract to pay a single payment of R100,000,000 in 5 years with a yield to maturity of approximately 6.11% assuming coupons are paid annually. Mashanda calculates the present value of this contract to be R74,339,294. This is the amount he intends to invest today to immunize the contract. Mashanda is building a suitable portfolio and already holds the RSA government bonds shown in Exhibit 2.

Exhibit 2: Existing Portfolio Bonds

Bond	Market Price (R)	Total Market Value (R)	Duration	Total Rand Duration
Bond R	99.53	30,639,442	?	612,789
Bond T	95.08	41,231,937	?	2,061,597

Mashanda must choose a RSA government bond to complete the immunized portfolio. He has gathered the data shown in Exhibit 3.

Exhibit 3: Bonds Available to Complete Immunized Portfolio

Bond	Market Price (R)	Yield to Maturity	Modified Duration
Bond A	101.10	3.52%	22.4400
Bond B	98.10	3.80%	42.2453
Bond C	99.97	3.85%	45.9510

a) Calculate the duration of Bond R and Bond T.

b) Determine which bond (A, B, or C) is the most suitable for Mashanda to complete the immunized portfolio. Justify your response