Answer: The Civil Service system was instituted by (A) the Pendleton Act.
Explanation: The Pendleton Act was passed in 1883, that is to say during Chester A. Arthur's presidency. It aimed at solving the problem of political patronage, which was considered to be a form of corruption, by establishing the Civil Service system. This system consisted in hiring people based on their merits and not on their relationship with certain individuals that held positions in government. Therefore, potential employees now had to go through an exam.