Typically, the ____ function is used to "assemble" a string from smaller pieces until a complete line of characters is ready to be written, either to the standard output device or to a file.

A) strcpy()
B) strcat()
C) sscanf()
D) sprintf()

The `sprintf()` function is used to assemble a string from smaller pieces, formatting it according to specified criteria, and then storing the result in a string variable. This makes it ideal for preparing a complete line of characters before outputting.