Final answer:
The adverb in the sentence 'She ran happily along the path' is 'happily.'
Step-by-step explanation:
The adverb in the sentence 'She ran happily along the path' is 'happily.'
Adverbs act as modifiers of verbs, describing their time, place, reason, or manner. In this case, 'happily' describes the manner in which she ran.