Read the following paragraph:
"Smartphones and basic mobile phones both allow us to make calls, but they are quite different. Smartphones are much more advanced; they have bigger screens and offer internet access, apps, and better cameras. Basic phones, however, are simpler. They are usually cheaper and have longer battery life, but they lack most of the advanced features of a smartphone."
What is the main difference highlighted between smartphones and basic mobile phones?
A) Their ability to make calls.
B) Their screen size and advanced features.
C) Their brand and color options.
D) Their durability in water.