Read the following context and choose the best option to answer the question.
Context: We just could n't have such a terrible sight in one of our pictures . After a little more walking around we decided to leave . When we got outside San Antonio I began thinking about the history of the state . I thought about Travis ' letter and hoped that we as people have learned a few things since those days about helping others .
Question: What is meant by Travis ' letter ?
Options: 
A. Travis is country Singer Randy Travis , who has hit on hard times .
B. None of the above choices .
C. Travis has to do with a signer of the Declaration of Independence .
D. Travis was a War hero Associated with a battle at San Antonio 's Alamo and he wrote a letter which described San Antonio .


D