B. By prefixing a variable with Caller. inside a Custom Tag, you tell ColdFusion to make the variable available to the calling page.
A2:
B and C. By default, A and D will not be seen. B is the first file that would be found. C is the default Custom Tags directory.
A3:
A. The code in B simply creates a variable, not a default value. C creates a hidden form variable, which has no direct effect on the Custom Tag. D explicitly passes a Custom Tag attribute and value, but it does not set a default.
