$2)$ Management control systems can typically be placed into one of two broad categories: Centralized or Decentralized. While most businesses may start as centralized, they may shift towards a decentralized system over time. Which of the following would be considered a drawback of a decentralized system?

A$)$ Duplication of activities

B$)$ More specialization

C$)$ Optimal decision$-$making

D$)$ Slower decision$-$making