The correct answer is B. An initiative
Step-by-step explanation:
In the politics of the U.S. and other countries there are different ways voters can have an influence on the legislation and the government, including referendums, recalls, direct elections and initiatives each one with different purposes and used in different cases depending on the type of influence voters want to have in the legislation. In the case of initiatives, these are a mechanism voters have to propose new statutes or amendments to the constitution or law that need to be approved by the voters or considered by the parliament. This means this type of reform measure allow citizens of a nation to modify some part of the law by putting a proposed modification or law for public approval. Thus, if voters want to change a law about taxes or any other law the reform measure they need could use is an initiative, because this type of measure aims at proposing a new law or some modification of existing laws, which is exactly the purpose of the case presented in the question.