In a Typical Two-Component Signal Transduction System

In a typical two-component signal transduction system

A) the sensor kinase senses the environment and the response regulator directly alters transcription.
B) both the sensor kinase and the response regulator sense the environment.
C) both the sensor kinase and the response regulator directly alter transcription.
D) the sensor kinase directly alters transcription and the response regulator senses the environment.