不太理解ARM最后那三步是什么意思，可以通过画图解释一下吗？

问题如下：

A borrower is considering three competing mortgage loan offers from her bank. The amount borrowed on the mortgage is $100,000 with monthly compounding.

The rate on the ARM resets at the end of the year 3. Assuming the ARM is reset at 5.5% (i.e. the remaining balance on the loan will now be repaid with 5.5% nominal annual interest), which of the three loans will have the smallest monthly payment after the rate reset at the end of year 3?

选项：

A.30-year ARM B.15-year fixed-rate loan C.

30-year fixed-rate loan.

解释：

After year 3 the 30-year fixed-rate loan has the lowest payment. The loan payments, summarized in the table, are calculated using a financial calculator following the table.

Payment on the 30-year fixed is:

N = 12×30= 360; I/Y= (5/12) = 0.41667; PV= -100,000; FV = 0; calculate PMT=536.82

Payment on the 15-year fixed is:

N = 12×15= 180: I/Y= (4.385/12) = 0.36542; PV =-100,000; FV=0; calculate PMT=759.13

Calculations for the ARM

Initial payment

N = 12×30 = 360; I/Y = (3.75 / 12) = 0.31250; PV = -100,000; FV = 0; calculate PMT = 463.12

Balance at end of year 3:

N = 12×27 = 324; I/Y = (3.75 / 12) = 0.31250; FV = 0; PMT = 463.12; calculate PV = 94,270.54

Payment after the end of year 3:

N = 324; I/Y = (5.5 / 12) = 0.45833; PV = 94,270.54; FV = 0; calculate PMT = 559.15