Final answer:
Out of the given options, LLOOKUP is not a valid lookup function. The correct name for the function is VLOOKUP, which stands for vertical lookup.
Step-by-step explanation:
Out of the given options, LLOOKUP is not a valid lookup function. The correct name for the function is VLOOKUP, which stands for vertical lookup. It is used to search for a value in the first column of a table and retrieve a corresponding value from another column. Similarly, HLOOKUP is a valid lookup function which stands for horizontal lookup, used for searching horizontally across rows.
LOOKUP is a generic lookup function that can be used in both horizontal and vertical directions. It allows you to search for a value in a specified range and retrieve a corresponding value from another range.