What statement about technology and the COVID$-19$ pandemic indicates the importance of synchronous communication to daily life?

a$.$ News websites posted regularly updated "hot spots" and$/$or vaccine distribution statistics on interactive maps, which became extremely popular.

b$.$ Colleges and universities began to introduce more classes which could be attended whenever a student had time to watch a prerecorded lecture.

c$.$ The video communication app Zoom rose in popularity and became a household name.

d$.$ TikTok dances traveled across national borders over the course of a single day and became a viral phenomenon.