Given a text T, and several options, according to the question posed in the text T to choose the most appropriate option from the options as the answer, please directly output the most appropriate option, do not need to output the explanation.

Jules Bianchi is a bond analyst for Maneval Investments, lnc. Bianchi gathers data on three corporate bonds, as shown in Exhibit 1.
| Exibit 1.Selected Bond Data |
| Issuer | Coupon Rate | Price | Bond Description |
| Ayrault， lnc.(A I) | 5.25% | 100.200 | C aIlable at par in one year and two |
| years from today |
| Blum， lne.(BI) | 5.25% | 101.300 | Option-free |
| Cresson Enterprises(CE) | 5.25% | par in one year from | 102.100 | Put able at |
| today |
| Note：Each bond has a remaining maturity of three years， annual coupon payments， and a |
| credit rating of BBB. |


To assess the interest rate risk of the three bonds, Bianchi constructs two binomial interest rate trees based on a 10% interest rate volatility assumption and a current one-year rate of 1%. Panel A of Exhibit 2 provides an interest rate tree assuming the benchmark yield curve shifts down by 30 bps, and Panel B provides an interest rate tree assuming the benchmark yield curve shifts up by 30 bps. Bianchi determines that the AI bond is currently trading at an option-adjusted spread (OAS) of 13.95 bps relative to the benchmark yield curve.
| 7.0037% |
| 4.6947% |

| Panel B Interest Rates Shift Upby30bps |
| 7.7432% |

| Exhibit 2.Binomial Interest Rate Trees |
| Panel A Interest Rates Shift Down by30bps |
| Year 0 | Year 1 | Year 2 |

| 3.7000% |
| 4.3000% |


Armand Gillette, a convertible bond analyst, stops by Bianchi's office to discuss two convertible bonds. One is issued by DeLille Enterprises (DE) and the other is issued by Raffarin Incorporated (RI). Selected data for the two bonds are presented in Exhibits 3 and 4.
| Exhibit 3 Selected Data for DE Convertible Bond |
| Issue price | E 1， 000atpar |
| Conversion period | 13September 20X 5to |
| 12 |
| September 20X 8 |
| Initial conversion price | C 10.00per share |
| Threshold dividend | e 0.50per share |
| Change of control conversion price | 68.00per share |
| Common stock share price on issue date | 8.70 |
| Share price on17September20X 5 | e9.10 |
| Convertible bond price on17September20X 5 | C1，123 |



| Exhibit 4 Selected Data for RI Convertible Bond |
| Straight bond value | 6978 |
| Value of embedded issuer call option | 643 |
| Value of embedded investor put option | 626 |
| Value of embedded call option on issuer's stock | e147 |
| Conversion price | 612.50 |
| Current common stock share price | 611.75 |


Gillette makes the following comments to Bianchi:■ “The DE bond does not contain any call or put options but the RI bond contains both an embedded call option and put option. I expect that DeLille Enterprises will soon announce a common stock dividend of €0.70 per share.”■ “My belief is that, over the next year, Raffarin's share price will appreciate toward the conversion price but not exceed it.”
Based on Exhibit 1, which key rate duration is the largest for the BI bond?
Option A:One-year key rate duration
Option B:Two-year key rate duration
Option C:Three-year key rate duration

Answer: C