What are two characteristics of synchronous calls to APIs? (Choose two.)

What are two characteristics of synchronous calls to APIs? (Choose two.)
A . They can be used only with certain programming languages.
B . They make your application less portable, so asynchronous calls are preferred.
C . They can add perceived latency to your application if data is not received.
D . They block until a response is returned from the servers.
E . They do not block while waiting for the API to be processed.

Answer: CE

Explanation:

Reference: https://docs.cloudmgmt.cisco.com/display/40API/Synchronous+and+Asynchronous+APIs