The correct answer is B.
OBJ-3.3: A Safety Instrumented System (SIS) is composed of sensors, logic solvers, and final control elements (devices like horns, flashing lights, and/or sirens) used to return an industrial process to a safe state after predetermined conditions are detected. The human-machine interface (HMI) provides the input and output controls on a PLC to allow a user to configure and monitor the system. In this scenario, Jason is sitting at a control panel with buttons and switches that are used to manually control the PLCs located throughout the reactor plant. Ladder Logic is a graphical, flowchart-like programming language used to program the special sequential control sequences used by a programmable logic controller (PLC). The data historian is a type of software that aggregates and catalogs data from multiple sources within an industrial control system’s control loop.