In this task, you are given a context, a subject, a relation, and many options. Based on the context, from the options select the object entity that has the given relation with the subject. Answer with text (not indexes).
Q: Context: Jakob Stoustrup is a Danish Scientist in the area of Control Theory at Pacific Northwest National Laboratory since 2014 . He has an extensive publication record in the areas of Robust Control and Fault Tolerant Control , as well as in a long range of applications of control theory ., In mathematics, a dynamical system is a system in which a function describes the time dependence of a point in a geometrical space. Examples include the mathematical models that describe the swinging of a clock pendulum, the flow of water in a pipe, and the number of fish each springtime in a lake., Control theory is an engineering method that deals with the behavior of dynamical systems with inputs, and how their behavior is modified by feedback. The usual objective of control theory is to control a system, often called the "plant", so its output follows a desired control signal, called the "reference", which may be a fixed or changing value. To do this a "controller" is designed, which monitors the output and compares it with the reference. The difference between actual and desired output, called the "error" signal, is applied as feedback to the input of the system, to bring the actual output closer to the reference. Some topics studied in control theory are stability (whether the output will converge to the reference value or oscillate about it), controllability and observability., In control theory, observability is a measure for how well internal states of a system can be inferred by knowledge of its external outputs. The observability and controllability of a system are mathematical duals. The concept of observability was introduced by American-Hungarian engineer Rudolf E. Kalman for linear dynamic systems., Subject: jakob stoustrup, Relation: occupation, Options: (A) clock (B) engineer (C) engineering
A:
engineer