The correct answer is B. Enraptured.
Enraptured means to be filled with great delight or pleasure. It is often used to describe the feeling of being completely absorbed in something, such as a beautiful piece of music or a romantic encounter.
Animated means full of life and energy. It can be used to describe someone who is very lively and enthusiastic, or something that is full of movement and excitement.
Bewildered means confused and unable to understand something. It can be used to describe someone who is lost or confused, or something that is very complex or difficult to understand.
Fitful means characterized by sudden and unpredictable changes. It can be used to describe someone who is restless or irritable, or something that is not consistent or reliable.
In this case, the best synonym for ecstatic is enraptured. This is because enraptured captures the feeling of intense joy and pleasure that is often associated with ecstasy. Animated, bewildered, and fitful do not capture this feeling as well.