Sorry for such late an answer, but I believe its A) Predicate Nominative.
Answer:
The value of going to the bay had diminished. The explanation for this is that he had just finished an exceptionally stressful trial that he had imposed on himself.
Stress is a <span>pressure or tension exerted on a material object.</span>
<span> He immediately let go of </span>his<span> own, and fiercely attacked the other </span>Dog<span> to get </span>his<span> larger piece from him.</span>
