Rosemary Began Work as a Bank Teller a Year Ago

Rosemary began work as a bank teller a year ago. During the first three months, she spent two days a week in formal training, learning about different financial transactions, how the bank's computer system worked, and other aspects of the job. Over the course of the year, she has also learned from experience how to get around "bugs" in the computer system, and from her coworkers how to deal with difficult customers and, sometimes, difficult bosses. Which of the following terms best describes what Rosemary learned outside of formal training?

A) Informal knowledge.
B) Worker sub-culture.
C) Organizational culture.
D) Tacit skills.