Bad Qubits — Learn Quantum by Doing

Multiple choice

A stabilizer code is called DEGENERATE under which precise condition on two distinct correctable errors E_a and E_b?

They anticommute with every stabilizer generator
They have the same weight but act on disjoint sets of qubits
Their product lies in the stabilizer group, E_a^dagger E_b in S, so they act identically on every codeword and share the same syndrome and recovery
Their product equals the identity, E_a^dagger E_b = I, so they are the same error