The correct answer is A. stable. Joys and tensions are ephemeral aspects of life, meaning that they are temporary and fleeting. They come and go, and they do not last forever. This is in contrast to stable aspects of life, such as our relationships, our jobs, and our homes. These things are more permanent and less likely to change.
Option B, permanent, is incorrect because joys and tensions are not permanent. They come and go, and they do not last forever.
Option C, spiritual, is incorrect because joys and tensions are not necessarily spiritual in nature. They can be caused by a variety of factors, both physical and emotional.
Option D, ethical, is incorrect because joys and tensions are not necessarily ethical in nature. They can be caused by a variety of factors, both good and bad.