Final answer:
The best answer is 'c) exhibit homeostasis', as all living things maintain a stable internal environment. This process is known as homeostasis and is a universal characteristic of life.
Step-by-step explanation:
The statement that best completes the given sentence about all living things is 'c) exhibit homeostasis'. All living things are capable of maintaining a constant internal environment, which is known as homeostasis. Although living things are composed of one or more cells, not all are multi-cellular, so option a) may not be applicable in the context of unicellular organisms like bacteria. While all living things do exhibit some form of movement, either internally or toward stimuli, it is not the definitive characteristic because some move in ways that are not overtly noticeable. Similarly, not all living organisms are sensitive to all types of environmental stimuli, as different species respond to different stimuli, so option d) is not universally applicable.
In contrast, homeostasis is a fundamental characteristic of all living organisms, which allows them to regulate their internal environment to maintain a stable, constant condition, necessary for their survival. Examples of homeostasis include the regulation of body temperature in mammals, or the maintenance of pH levels in the blood.