In

In

A) inactivation of certain repressor proteins by elevated temperature.
B) denaturing of DNA in the promoters in the genes of heat sensitive proteins.
C) synthesis of alternative sigma factors at high temperatures, which then regulate transcription of heat shock genes.
D) increasing the promoter affinity of already existing polymerase sigma factors at high temperatures.
E) coli, the heat shock response, switching off the synthesis of some proteins and switching on of different proteins, is mediated by