Which of the following statements is true regarding the time frame dimension of an integrated report?
选项：

A: The length of each time frame for short, medium, and long term is decided by the organization. There is no set answer for establishing the length for each term.
B: The length of the short-term perspective must be one fiscal year.
C: A long-term perspective is required for all organizations which have been in existence for ten years or more.
D: The short term must be one or two years, the medium term may be two to five years, and the long term may be five or more years.