- The deer ran swiftly through the forest.
- Ran swiftly through the forest, the deer.
- Through the forest, ran the deer swiftly.
- The deer swiftly ran through the forest.
The correct sentence structure in English is Subject-Verb-Adverb-Object. The subject (the deer) should be followed by the verb (ran), then the adverb (swiftly), and finally, the object (through the forest). The correct option (a) follows this structure.