The correct answer is A. 112.
The labour turnover rate is the percentage of workers who leave a company during a given period of time. It is calculated by dividing the number of workers who leave by the average number of workers employed during the period.
In this case, the labour turnover rates are 20%, 10% and 6% respectively under Flux method, Replacement method and Separation method. This means that 20% of the workers who were employed in the Flux method left during the quarter, 10% of the workers who were employed in the Replacement method left during the quarter, and 6% of the workers who were employed in the Separation method left during the quarter.
The number of workers replaced during the quarter is 80. This means that 80 workers were hired to replace the workers who left during the quarter.
To calculate the total number of workers recruited and joined, we need to add the number of workers who left to the number of workers who were hired. This gives us 112.
Option B is incorrect because it is the number of workers who left during the quarter. Option C is incorrect because it is the number of workers who were hired to replace the workers who left during the quarter. Option D is incorrect because it is the average of the labour turnover rates.