The ratio of error found before s/w delivery and to the total errors (before and after) is called:

Correct option is C

Defect Removal Efficiency (DRE) measures the effectiveness of the quality assurance process in identifying and fixing defects before software delivery. It is calculated as the ratio of defects found before delivery to the total number of defects found both before and after delivery. A high DRE indicates a thorough and effective testing process, reducing the likelihood of defects escaping into production.