The answer is (C): Ternary. The da capo notation (usually "D.C. al fine") means "from the head." When the composer uses the da capo notation at the end of a section, the reader begins again at the "fine" indicated in the composition. In a da capo ternary style, "fine" follows the first section and "D.C. al fine" follows the second section. The third section is the repeated first section.
