A and D. Strings always can be accessed as lists. Dates can be treated as strings and therefore are lists (usually delimited by slashes or hyphens). Arrays and structures, however, can never be accessed as lists.
A2:
A, C, and D. Because it is an empty string, B is not valid. (ColdFusion will not throw an error, but the list will always contain one element.)
A3:
A, B, C, and D. By default, the list has one element. If a space is used as a delimiter, the list has two elements. If two characters are used as delimiters (for example, er or no), the list has three elements. If the delimiter contains all the characters Ben Forta, the list has no elements at all, just delimiters.