Six Sigma quality control?

A.) is a tool that is superior to TQM in achieving top-notch quality in manufacturing a product.

b.) consists of a disciplined, statistics-based system aimed at producing not more than 2.5 defects per million iterations.

c.) is based on three principles: (1) all work is a process, (2) all processes have variability, and (3) all processes create data that explain variability.

d.) is the best practice for managing manufacturing and assembly activities.

e.) is a disciplined, statistics-based approach to manufacturing or assembling a product and results in five defects per million iterations when implemented properly.