Which of the following is the safest level of exposure to secondhand smoke

In many ways, the regulation of the genes of a particular group of viruses will be similar to the regulation of the host genes. therefore, which of the following would you expect of the genes of a bacteriophage? a) regulation via acetylation of histonesb) positive control mechanisms rather than negativec) control of more than one gene in an operond) reliance on transcription activators