Q:Write a multi-choice question for the following article, with the given choices and answer: Article: In 1989 an 8.2 earthquake almost flattened America, killing over 30,000 people in less than four minutes. A father rushed to the school where his son was supposed to be, only to discover that the building was as flat as a pancake. After the shock, he remembered the promise he had made to his son: "No matter what happened, I'll always be there for you!" And tears began to fill his eyes. As he looked at the pile of ruins that once was the school, it looked hopeless, but he kept remembering his promise to his son. Remembering his son's classroom would be in the back right corner of the building, he rushed there and started digging. Other parents tried to pull him off the ruins, saying: "It's too late! _ 're all dead! You can't help!" He replied, "Are you going to help me now?" The fire chief showed up and tried to pull him off the school's ruins saying, "Fires are breaking out, explosions are happening everywhere. You're in danger. We'll take care of it. Go home." This loving, caring American father asked, "Are you going to help me now?" The police came and said, "You're, anxious and it's over. Go home. We'll handle it!" He replied, "Are you going to help me now?" No one helped. Courageously he went on alone. He dug for eight hours...12 hours...24 hours...36 hours...then, in the 38th hour, he heard his son's voice. He screamed his son's name, "ARMAND!" He heard back, "Dad! It's me, Dad! You promised no matter what happened, you would always be there for me! You did it, Dad!" "What's going on in there? How is it?" the father asked. "There are 14 of us left out of 33, Dad. " "Come out, boy!" "No, Dad! Let the other kids out first, because I know you'll get me! No matter what happens, I know you'll always be there for me!" Options: A Because he promised his wife he would take care of their son. B Because others persuaded him to do so. C Because he promised his son that he would be with him whatever happened. D Because his son was his only child. Answer: C Because he promised his son that he would be with him whatever happened. Question:
A:
Why did the father keep digging?