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As the architect of a seismic data analysis system utilizing an Apache Hadoop cluster for its ETL process, you face a challenge where the ETL process takes several days to complete due to computational complexity. Upon investigation, you find that the sensor calibration step was omitted. To systematically incorporate sensor calibration in the future, what should you do?
A
Develop an algorithm to predict data variance from the last MapReduce job based on calibration factors and apply corrections.
B
Append sensor calibration data to the ETL output, providing users with documentation to manually apply calibration.
C
Introduce a new MapReduce job for sensor calibration on raw data, ensuring it precedes all other jobs in the ETL process.
D
Adjust existing MapReduce jobs to perform sensor calibration as the initial step.