单选题 According to the passage, in the Cepheid variable method all of the following have a significant role in the calculation of the distance of a galaxy EXCEPT

• (A) The intrinsic luminosity of a Cepheid
• (B) The comparative luminosity of ordinary stars
• (C) The observed brightness of the Cepheid
• (D) The data suggesting the expansion of the universe
• (E) The correction of the period-luminosity relation for the star being observed