Identify the real subject in the following sentence: The decision of the engineers was to double the chlorine concentration in the water treatment process.

“second, the reviewer must know the current trends in movie-making. what types of technology are available? are audiences more drawn to low-budget, independent films, or huge, explosive blockbusters? ” the passage above is explaining a. important information you must have before watching a movie c. what a reviewer must understand to write effective reviews b. why it is impossible to understand the movie business d. how to break into the cinematography business