The significance of Fred Griffith's experiment in which he used two strains of Streptococcus ...

The significance of Fred Griffith's experiment in which he used two strains of Streptococcus pneumoniae is that
 
  a. the semiconservative nature of DNA replication was finally demonstrated.
  b. it demonstrated that harmless bacterial cells had become permanently transformed through a change in the bacterial hereditary system.
  c. it confirmed that each cell of a given species contains the same amount of DNA.
  d. it demonstrated that radioactively labeled bacteriophages transfer their DNA but not their protein coats to their host bacteria.
  e. it demonstrated that mice can change the hereditary content of bacteria.