Which of the following examples demonstrates that disruptive technologies become competitive necessities?

a$)$ The Internet was disruptive in the $1990$s but today it is difficult for a business to thrive without a robust web presence

b$)$ Cloud computing and mobility were disruptive in the $2000$ s$,$ now more people connect to the Internet and cloud services with smart phones and tablets than PCs$.$

c$)$ In the $2010$ s$,$ Big Data was a major disruptor but today business analytics $($BA$)$ is being used by most companies and data analysts$/$scientists are being hired at accelerating rates.

d$)$ All of the above