In the early 21st century, around 1.7 billion people worldwide now belong to the consumer class

____ are sets of computerized tools and displays that automate training, documentation, and phone support; integrate this automation into applications; and provide support that's faster, cheaper, and more effective than traditional methods.

Fill in the blank(s) with the appropriate word(s).

Save your work on _______________

a. numerous hard copies b. completion c. a backup disk d. a cloud storage system