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.

Katrina Black, portfolio manager at Coral Bond Management, Ltd., is conducting a training session with Alex Sun, a junior analyst in the fixed income department. Black wants to explain to Sun the arbitrage-free valuation framework used by the firm. Black presents Sun with Exhibit 1, showing a fictitious bond being traded on three exchanges, and asks Sun to identify the arbitrage opportunity of the bond. Sun agrees to ignore transaction costs in his analysis.
| Exhibit 1.Three-Year， e100par， 3.00%Coupon， Annual Pay Option-Free Bond |
| EurexNYSE EuronextFrankfurt |
| Price6103.79566103.78156103.7565 |


Black shows Sun some exhibits that were part of a recent presentation. Exhibit 3 presents most of the data of a binomial lognormal interest rate tree fit to the yield curve shown in Exhibit 2. Exhibit 4 presents most of the data of the implied values for a four-year, option-free, annual pay bond with a 2.5% coupon based on the information in Exhibit 3.
| Exhibit 2.Yield to Maturity Par Rates for One-， Two-， and |
| Three-Year Annual Pay Option-Free Bonds |
| One-year | Two-year | Three-year |
| 1.25% | 1.50% | 1.70% |



| Exhibit 3.Binomial Interest Rate Tree Fit to the Yield Curve(Volatility=10%) |
| Current | Year 1 | Year 2 | Year 3 | Year 4 |
| 1.2500% | 1.8229% | 1.8280% | 2.6241% | Node 4-1 |
| 1.4925% | Node 2-2 | Node 3-2 | 4.2009% |
| 1.2254% | 1.7590% | 3.4394% |
| Node 3-4 | 2.8159% |
| Node 4-5 |



| Year Or | Year 1 | Year 2+ | Year 3 | Year 4 |
| 103.4960 | 101.7877 | 100.7696 | 99.8791 | 102.5000++ |
| Node 1-2 | 101.5168+ | 100.3442102.5000+ |
| 102.1350 | 100.7282102.5000++ |
| 101.0449+ | 102.5000+ |


Black asks about the missing data in Exhibits 3 and 4 and directs Sun to complete the following tasks related to those exhibits:Task 1 Test that the binomial interest tree has been properly calibrated to be arbitrage-free.Task 2 Develop a spreadsheet model to calculate pathwise valuations. To test the accuracy of the spreadsheet, use the data in Exhibit 3 and calculate the value of the bond if it takes a path of lowest rates in Year 1 and Year 2 and the second lowest rate in Year 3.Task 3 Identify a type of bond where the Monte Carlo calibration method should be used in place of the binomial interest rate method.Task 4 Update Exhibit 3 to reflect the current volatility, which is now 15%.
If the assumed volatility is changed as Black requested in Task 4, the forward rates shown in Exhibit 3 will most likely:
Option A:spread out.
Option B:remain unchanged.
Option C:converge to the spot rates.

Answer: A