Final answer:
The best fit for the described symptoms of stress is likely chronic stress, which can lead to a range of psychophysiological disorders due to prolonged exposure to stressors and physiological reactions that are beneficial in acute situations but detrimental when prolonged.
Step-by-step explanation:
The symptoms of stress involving muscle tension, heart palpitations, insomnia, and gastrointestinal upsets can refer to various stress-related conditions. However, as the symptoms are not specified to be either short-lived or part of a specific traumatic event, the best fit for a general, ongoing stress condition with physical manifestations is likely chronic stress (B). Chronic stress is defined by prolonged exposure to stressors that can result in a range of physiological responses and health issues. It's distinguished from acute stress disorder (A) which typically occurs as a response to trauma and has a more immediate onset. Physical stress (C) is often related to acute physical strain or injury rather than the listed symptoms, and somatic stress (D) is not a commonly used term in this context.
Chronically elevated stress levels can cause psychophysiological disorders, where psychological factors exacerbate or contribute to physical symptoms and diseases. Examples include cardiovascular disorders, asthma, and gastrointestinal issues such as irritable bowel syndrome (IBS), which could involve an imbalance of serotonin affecting well-being and gastrointestinal function. Stress triggers physiological reactions which are beneficial in acute situations but detrimental when prolonged, such as increased cortisol levels leading to reduced immunity, or the bodily resources being taxed to a point leading to exhaustion and related health issues.