Which shape actually starts two independent calls before waiting for either result?

Which shape actually starts two independent calls before waiting for either result?

1. `val a = async { first() }.await(); val b = async { second() }.await()`
2. `val a = async { first() }; val b = async { second() }; use(a.await(), b.await())`
3. `val a = first(); val b = second(); use(a, b)`
4. `GlobalScope.async { first(); second() }.await()`