The correct answer is B, as the fact that in the Massachusetts Bay Colony, all citizens were taxed in order to support the church support the statement that says that the Puritans didn't believe in a true separation of church and state.
Church-State separation is the legal and political concept by which state and religious institutions are kept separate and the Church does not intervene in public affairs; each party having an autonomy to deal with issues related to its spheres of influence.
One way to emphasize this separation is the fact that the State does not contribute to the Church's funding. Therefore, the fact that in the Massachusetts Bay Colony citizens' taxes were collected to support the Church is a clear example that their Puritan inhabitants did not believe in this separation.