Final answer:
Antonio Vivaldi is the composer who developed the concerto structure, ritornello form, idiomatic writing for strings, and programmatic writing among the options provided.
Step-by-step explanation:
The composer credited with the contributions of developing the concerto structure, being a leader in establishing ritornello form, developing idiomatic writing for strings, and incorporating programmatic writing is Antonio Vivaldi. Vivaldi's work in the Baroque period was instrumental in shaping the concerto as a musical form, and his influence is evident in the music of many following composers. Among the list provided, Vivaldi best fits the description of these contributions to the musical landscape of his time.