Compiles Then Crashes

void take(std::unique_ptr<Widget> p);

std::unique_ptr<Widget> w = std::make_unique<Widget>();

take(w);                                 // A
take(std::move(w));                      // B
auto w2 = w;                             // C
std::unique_ptr<Widget> w3(w.get());     // D

Exactly one of these lines compiles and then destroys the same Widget twice. Which one?