Which best describes building blocks?

Answer: Collections of formatting information that can be used as the basis for a new document

Building blocks can help maintain any formatting you have applied in your document like bold, insertion of headers and footers, centering, and many other options. It allows you to create reusable chunks of content and can be used over and over again especially on some types of writing such as legal field.

since it can be assumed that what aslam is making is a template by compiling all the commonly used excel formatting in several worksheets in an excel document, aslam can choose to save it using the .xltx or .xltm format instead. thus, aslam can distribute the templates he has made to his team members in an easier manner.