A Base constructor calls a virtual member on *this while constructing a Derived object. W…

A Base constructor calls a virtual member on *this while constructing a Derived object. Where can that call dispatch?

1. To the final overrider in Base or one of its bases, not to Derived.
2. Always to Derived because the allocation already has Derived size.
3. Only to a free function selected by argument-dependent lookup.
4. The call is always a compile-time error.