Which of the reasons below will possibly be responsible for the disappearance of desktop and portable computers by $2031?$

A$.$ Desktop and portable computers will be replaced by mobile devices of many different types.

B$.$ Smart watches will replace the existing desktop and computers.

C$.$ There will be no need of using any computing devices by $2031.$

D$.$ Tanita is a mobile device which will replace all kinds of computers.

E$.$ Google glass will replace the need to use computers.