Answer:
B. Both were examples of Arab-Israeli conflicts in the twentieth century.
Step-by-step explanation:
The Six-Day War was fought by Israel against Egypt, Jordan, and Syria. This war was fought after the Arab-Israeli War where the relation between Israel with its neighboring nations soured.
The Yom Kippur War was fought between Syria and Egypt against Israel in an attempt to get back the lands lost during the Arab-Israeli War of 1967. This attack during the holiest day in the Jewish calendar led to a ceasefire between the warring nations.
The one similarity between these two wars is that they were both examples of Arab-Israeli conflicts in the 20th century.