Questions: The study of the features that enrich life, such as happiness, hope, creativity, and courage is known as psychoneuroimmunology, positive psychology, subjective-well-being, health psychology.

The answer is the second one: positive psychology.

Explanation for each option:

1. Psychoneuroimmunology: This field studies the interaction between psychological processes and the nervous and immune systems of the human body. It does not specifically focus on features that enrich life such as happiness, hope, creativity, and courage.

2. Positive psychology: This is the correct answer. Positive psychology is the scientific study of what makes life most worth living, focusing on positive aspects such as happiness, hope, creativity, and courage.

3. Subjective well-being: This term refers to how people experience the quality of their lives and includes both emotional reactions and cognitive judgments. While it is related to happiness, it is not the study of the features that enrich life.

4. Health psychology: This field focuses on how biological, psychological, and social factors affect health and illness. It does not specifically study the features that enrich life.

Summary: The study of the features that enrich life, such as happiness, hope, creativity, and courage, is known as positive psychology.