- She read the letter silently.
- The letter read she silently.
- Silently read she the letter.
- The letter she read silently.
The correct sentence structure in English is Adverb-Subject-Verb-Object. The adverb (silently) should come first, followed by the subject (she), the verb (read), and finally, the object (the letter). The correct option (a) follows this structure.