Which of the following terms indicates a slight, pleasant smell?

The term "fragrant" specifically refers to a pleasant smell, often associated with flowers, perfumes, or other appealing scents. It conveys the idea of an enjoyable aroma that can uplift one's mood or enhance an experience. In this context, "fragrant" is the most fitting choice, as it directly indicates a slight and pleasant olfactory presence.

The other terms differ significantly in meaning and connotation. "Pungent" usually describes a strong, sharp smell that can be overpowering, often associated with spices or strong odors. "Repugnant" suggests something that is offensive or distasteful and does not relate to pleasant smells at all. "Aromatic," while it can imply a pleasant smell, often refers to strong or distinct scents, which may not necessarily be slight in nature. Thus, "fragrant" is the best choice as it embodies the concept of a mild and agreeable aroma.