Bad Qubits — Learn Quantum by Doing

Multiple choice

A qubit is in the state

(|0\rangle + |1\rangle)/\sqrt{2}

. Which statement describes it best?

It is rapidly oscillating back and forth between $|0\rangle$ and $|1\rangle$ .
It is secretly already 0 or 1; we simply don't know which until we look.
It is in a single quantum state — a superposition of $|0\rangle$ and $|1\rangle$ — and a measurement yields 0 or 1, each with probability 1/2.
It is physically in both $|0\rangle$ and $|1\rangle$ at the same time, like two parallel objects.