Once agreed upon by all parties, the governor signs a bill and it becomes a) official b) stamped c) authorized d) law

Once agreed upon by all parties, the governor signs a bill and it becomes law.
The bill is only the pre-form of a law and it requires to be voted and agreed on before it could become law. After this process, the governor signs the bill and only at that moment, the bill become officially a law of the state that must be followed.