In the linked implementation, under what circumstances could the head and tail references be equal?

One of the benefits of using macros in Access is to:

A) efficiently and accurately process database ad hoc queries from several remote locations. B) set the correct table relationships that will help to efficiently organize the data in a database. C) automate non-routine tasks within an Access database. D) decrease processing time within a database while simultaneously reducing potential errors in the processing of data.

Of the following properties, which one CANNOT be smoothly animated in a shape tween? Gradient fill, stroke size, width, transparent fill, blur filter.

What will be an ideal response?