The answer is (A) vertical mobility.
Vertical mobility refers to the movement of an individual or group from one social status to another, which can be either upward or downward. In this case, the inner-city youth moves from a lower socioeconomic status to a higher one by leveraging his basketball skills to gain a college scholarship and eventually a lucrative contract in the NBA. This upward movement in social and economic status is a clear example of vertical mobility.
Ascribed status is a social position assigned to an individual at birth or involuntarily later in life, based on characteristics such as race, gender, or family background. The scenario described involves the youth achieving success through his own efforts and skills, rather than being assigned a status based on inherent characteristics. Therefore, this option does not apply.
Horizontal mobility refers to a change in position within the same social level, such as changing jobs without a significant change in income or social status. The youth's movement from playing basketball in the neighborhood to playing professionally in the NBA represents a significant upward shift in social and economic status, not a lateral move. Thus, this option is not applicable.
Structural mobility occurs when societal changes enable a whole group of people to move up or down the social ladder. This scenario focuses on the individual achievements of the youth rather than broader societal changes affecting a group. Therefore, this option is not relevant to the given example.