Raisa took one cup of half olive-oil and half vinegar and poured it in a jar that had equal parts of olive-oil, vinegar, and water. If the result is a three-cup mixture of salad dressing, what portion of the dressing is olive-oil?

1. ক5/12
2. খ5/6✓
3. গ9/16
4. ঘ7/18