If a researcher varies the loudness of music in a factory to observe its effect on the rate of productivity of the employees,what is the independent variable

A)  loudness of music
B)  factory setting 
C)  employees
D)  rate of productivity

Loudness of Music

The perception of sound intensity, typically measured in decibels, reflecting how loud or soft music appears.

Independent Variable

The variable in an experiment that is manipulated or changed by the researcher to observe its effects on the dependent variable.

Productivity

Productivity is a measure of efficiency that quantifies the output generated per unit of input, such as the amount of goods and services produced per hour of labor.