Answer:
d. Becoming the Governor of Texas
Step-by-step explanation:
Although I would say that she accomplished all of the mentioned things, I would go with d, because she was the acting governor of Texas for only one day. She was the first African American in the US Senate from Southern States in the period between 1973 and 1979. She gave two keynotes in 1976 and 1992, and additionally she even gave an introduction speech during the impeachment of Nixon.