To position the date and closing lines correctly in a modified block letter, set a tab at ____.

Answer the following statements true (T) or false (F)

1. The insert library module automatically expands the size of the string to accommodate the inserted characters. 2. The isWhiteSpace library function returns True if its argument is displayed on the screen with white text instead of black. 3. Most programming languages do not allow access to individual characters in a string. 4. In a string, a space (such as the space between a first and last name) cannot be accessed by a subscript.

The __________ is added to the beginning or end of a number to validate the number's authenticity.

A. security digit B. token digit C. verification digit D. check digit