Bad Qubits — Learn Quantum by Doing

Multiple choice

In simulating fermions on a quantum computer, the Jordan-Wigner transformation maps each fermionic creation/annihilation operator to a qubit operator with a trailing string of which gates, in order to reproduce the fermionic exchange (anticommutation) signs?

A string of Z gates (e.g. a_j^dagger maps to (product over k<j of Z_k) times sigma^-_j)
A string of X gates that flip every qubit to the left
A single controlled-NOT gate between adjacent modes
A string of Hadamard gates applied to all qubits