TOEFL Reading: ETS-TOEFL阅读机经 - 87K22JMA365PA936L$

Which of the following can be inferred from the passage about the transformed R-strain pneumococci A. They had acquired the genetic information for producing a protective coating. B. They were unable to cause transformation in other strains of pneumococci. C. In the presence of heat-killed R-strain bacteria, they lost their virulence. D. They did not multiply as quickly as nontransformed cells did.