Question

which part of the formula references the worksheet?
○ sheet3!
○ sum
○ a12
○ a6:a19
a19,sheet3!a12)

Explanation:

In Excel formulas, the syntax to reference a worksheet is [WorksheetName]!, so "Sheet3!" is the part that references the worksheet. "SUM" is the function name, "A12" and "A6:A19" are cell references (not the worksheet reference part).

Answer:

A. Sheet3!