Answer:
A) G-mail
Explanation:
Android OS is from google so also is G-mail which is pre-installed on android devices, therefore this will be the easiest for her to set-up. During setup she can create a new account or connect an existing google account
Web 2.0 replacing the world wide web.
email was invented in the 70s
e-commerce was invented in the late 80s
arpanet was around the 70s as well