Which code fragment will produce a maximally entangled, or Bell, state?

Which code fragment will produce a maximally entangled, or Bell, state?
A . bell = QuantumCircuit(2)
bell.h(0)
bell.x(1)
bell.cx(0, 1)
B . bell = QuantumCircuit(2)
bell.cx(0, 1)
bell.h(0)
bell.x(1)
C . bell = QuantumCircuit(2)
bell.h(0)
bell.x(1)
bell.cz(0, 1)
D . bell = QuantumCircuit(2)
bell.h(0)
bell.h(0)