Kerry Is 6 Years Old, and When She Adds Numbers

Multiple Choice

Kerry is 6 years old, and when she adds numbers together she uses the sum strategy.Her older brother shows her the min strategy, and Kerry can see that this is a better strategy that will be much faster.The fact that Kerry didn't use the min strategy until her brother showed her how illustrates what type of deficiency?

A) operational
B) production
C) utilization
D) mediation