Which of the following is NOT mentioned as a cause for textings popularity？A．Redesign of m

Which of the following is NOT mentioned as a cause for textings popularity？

A．Redesign of mobile devices.

B．Rise of social media.

C．Promotion of cheaper wireless packages.

D．Increase in the number of adult texters.

请帮忙给出正确答案和分析，谢谢！