Skilled Typists Are Likely to Rely on Plans for Typing

Skilled typists are likely to rely on plans for typing, as shown by the fact that

A) Times between keystrokes are typically shorter than reaction times to external signals for the same individual keystrokes
B) Times between keystrokes are typically longer than reaction times to external signals for the same individual keystrokes, showing that the typists are busy planning
C) Typists plan for events like vacations and their children's education
D) This is what they are told to do in how-to-type books and websites