Uber offers a$/$n $\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_$ that is essentially a published guideline on how other developers can embed Uber into their own apps.

a$.$

API $($application programming interface$)$

b$.$

WebSockets protocol

c$.$

EDA $($Event$-$Driven Architecture$)$

d$.$

SOAP $($Simple Object Access Protocol$)$

e$.$

Cloud Endpoints