Which of the Following Is True About Mobile Optimized Sites

Which of the following is true about mobile optimized sites?

A) Mobile websites should only focus on task-based functionality, i.e. be a stripped-down version of the desktop site
B) Mobile-friendly experiences typically feature easy navigation, quick-to-load images, and streamlined text
C) Visitors to your mobile-optimized site will be at the same point in the purchase funnel as visitors to your desktop site
D) You should build your app before your mobile site