When async is added to a function:
async function example() {}
JavaScript guarantees:
The function always returns a Promise, regardless of what is returned inside.
Inside the function, await pauses execution until a Promise resolves.
Code appears synchronous even though it uses asynchronous behavior.
Analysis of each option:
A incorrect:
Not "sometimes"-an async function always returns a Promise.
B incorrect:
Async functions can be called just like normal functions.
C incorrect:
Async/await has nothing to do with classes specifically.
D correct:
This is the standard description:
"Async functions behave asynchronously but allow writing code that looks synchronous." JavaScript Knowledge Reference (text-only) async functions always return Promises.
await pauses execution of the async function.
Async/await syntax creates synchronous-looking code on top of asynchronous operations.