Callahan, who was born to working-class parents, just graduated from medical school and passed his medical board exams. He would be considered to have experienced __________ mobility.A.upwardB.structuralC.horizontalD.downward

The correct answer is A. Upward.

Here's the step-by-step reasoning:

1. Social mobility refers to the ability of an individual or family to move up or down the social and economic ladder within a society.

2. In the case of Callahan, he was born to working-class parents but has now graduated from medical school and passed his medical board exams. This suggests that he has significantly improved his educational and likely his economic status.

3. Therefore, Callahan has experienced upward mobility, as he has moved from a lower social or economic position (working-class) to a higher one (medical professional).

4. Structural mobility refers to changes in the social status of large numbers of people due to structural changes in society, not applicable in this case.

5. Horizontal mobility refers to the movement of an individual from one position to another within the same social level, also not applicable in this case.

6. Downward mobility refers to a lowering of one's social class, which is the opposite of what happened to Callahan.