In January 2003, the Medusco Investment firm has decided to present its performance history in compliance with the Global Investment Performance Standards (GILES). Medusco was formed on January 1, 1992, and has never before presented its performance results in compliance with the GIPS standards. Which of the following actions must Medusco take in order to claim GIPS compliance（）
A. Present GIPS - compliant performance results for the 5 - year period from January 1, 1998, through December 31, 2002, and report five additional years of non - GIPS - compliant performance with a disclosure explaining why the performance in the earlier years is not GIPS - compliant.
B. Retroactively comply with GIPS for periods after January 1 , 2000, and report non - GIPS - compliant performance results for the periods January 1, 1993, through December 31, 1999, with a disclosure explaining why these earlier years are not GIPS -compliant.
C. Present GIPS- compliant performance results for the 5 -year period from January 1, 1998, through December 31, 2002.