Bad Qubits — Learn Quantum by Doing

Multiple choice

Per this lesson, what physical mechanism makes interference fundamentally different from ordinary probabilities in quantum computing?

Measurement lets you read all 2^n amplitudes at once for free
Entanglement copies each qubit so both outcomes happen separately
Probabilities can be negative, allowing them to cancel
Amplitudes can be negative or complex, so contributions can cancel (destructive) or reinforce (constructive)