What Is the Purpose of Writs of Mandamus on Which

What is the purpose of writs of mandamus on which the Texas Supreme Court sometimes acts?

A) It is to remedy defects in justice by ordering lower courts or public officials to take a certain action.
B) It offers a higher court's opinion to a lower court in a case that has a high probability for appeal.
C) They provide written mandates that guide lower courts on decisions in civil cases.
D) They are used to stop a case from being heard in a lower court and to transfer it to a higher court.
E) They are decrees ordering the legislature to strike down unconstitutional laws.