Which of the following statements is NOT true about Rubisco?

A) It catalyzes the addition of CO₂ to ribulose 1,5-bisphosphate.
B) It is present in all organisms that use the Calvin cycle to fix CO₂.
C) It is found in the carboxysomes of autotrophic bacteria.
D) All species contain the same number of large and small subunits.
E) Its structure is highly conserved across bacterial groups and chloroplasts.