Helen is 72 years old and is a retired school teacher on a fixed income. She would like to buy a new computer so that she can communicate via email, follow friends and family on social media, and occasionally access recipes and gardening tips from the Web. An important thing to consider is that Helen has arthritis in her hands, making it difficult for her to work with small buttons and gadgets. So, of the following options, her best choice is probably a(n) ________.
a. e-book
b. nettop
c. desktop
d. smartphone