Read the following context and choose the best option to answer the question.
Context: It was kind of interesting , and everyone seemed really nice . By the time I had gotten there , he was half in the bag . It was really funny to see him so hyper , as he was drinking and excited cause the ex had gone and there was no real drama that night . So he was a little tipsy , and starts running around hanging out with everybody , and at one point keeps trying to get me to sit on his lap .
Question: What does the speaker mean by " half in the bag " ?
Options: 
A. None of the above choices .
B. The person was being friendly .
C. The person had just gotten out of a relationship .
D. The person is already drunk .


D