What is the difference between training "to standard" and training "to proficiency"?

What is the difference between training "to standard" and training "to proficiency"?

• A. Training to standard ensures meeting the minimum requirement; training to proficiency aims for performance beyond the standard.
• B. Training to standard is more expensive than to proficiency.
• C. Training to proficiency is only for leaders; standard is for all.
• D. There is no difference between training to standard and to proficiency.

Answer: (B)