Explanation:

This question asks for the state with the largest *percentage share* of the Scheduled Caste (SC) population. It's important to distinguish between the absolute number and the percentage. \nOption A: 'Uttar Pradesh' has the largest *number* of Scheduled Caste individuals in India. However, its percentage of SC population relative to its total population is around $\text{20.7\%}$ (as per $\text{2011}$ Census). \nOption B: 'Punjab' has the highest *percentage* of Scheduled Caste population among all Indian states. Approximately $\text{31.9\%}$ of Punjab's total population belongs to Scheduled Castes (as per $\text{2011}$ Census). Therefore, this option is correct. \nOption C: 'Maharashtra' has a significant SC population, but its percentage share is approximately $\text{11.8\%}$, which is much lower than Punjab. \nOption D: 'Andhra Pradesh' (undivided) had an SC population percentage of around $\text{17.1\%}$, which is also lower than Punjab. \nThus, while Uttar Pradesh has the largest numerical SC population, Punjab leads in terms of the proportion or percentage of SCs in its total population.