A, B , C, or D? Please help

What refrigerant has been approved for new household refrigerators and freezers

A(n) is a list at the beginning of a publication that shows the main topics in a book or report and provides page numbers to quickly access material.

1. how did the development of silicon chips impact computer usage? a. they improved the operating system b. they made it possible to use punch cardsc. they interpreted the binary system so that punch cards were no longer necessary d. they made it possible to produce computers small enough to fit on a desktop2. in what decade were personal computers, like the apple ii, introduced to the american public? a. 1890sb. 1920sc. 1970sd. 1990s3. why was the apple ii known as “the people’s computer”? a. it was made by the company peoplecomp.b. it made using computers easy for the general public.c. it was designed for several people to use at the same time.d. it was built by people.4. why was the term personal computer created? a. because the computers finally fit in the owner’s handb. because they were designed for individuals to usec. because you had to enter a personal password to access the computerd. because the computer was developed by a person