Option d is the correct answer. The transfer of the capital from Delhi to Daulatabad was ordered by Sultan Muhammad Bin Tughlaq in 1326. He aimed to centralize administration and connect the northern and southern regions. Despite building infrastructure, establishing a postal service, and providing support, the move faced challenges. Plague outbreaks, citizen dissatisfaction, and revolts undermined its success. By 1335, due to deteriorating conditions, the capital was moved back to Delhi. The shift's failure was attributed to logistical difficulties, public discontent, and an underestimation of regional complexities. Important Tips Transfer of capital-1326-27 CE: Muhammad Bin Tughlaq's decision to shift the capital from Delhi to Daulatabad in 1326-27 was driven by several key factors and faced subsequent failure: Reasons for Capital Transfer: Central Location: Tughlaq aimed to establish Daulatabad as a secondary capital to exert better control over the southern territories. He believed it was centrally located, equidistant from significant areas like Delhi, Gujarat, Lakhnauti, Telangana, and Dwarasamudra. Punitive Measure: Responding to alleged abusive letters from Delhi, Tughlaq sought to penalize the city's populace by depriving them of the capital. This is corroborated by Ibn Battuta and supported by Isami. Defense Against Mongols: Concerns about Mongol invasions influenced the move. Daulatabad's distance from the northwest frontier was seen as advantageous for protection. Southern Revolt: Tughlaq's transfer aimed to quell a significant uprising in the South and consolidate control over the region. Aesthetic Appeal: Tughlaq's attraction to Devagiri's beauty, possibly influenced by poets like Amir Khusrau, played a role. Failure of the Policy: Dissatisfaction and Discontent: The general population of Delhi was largely opposed to the relocation, and many citizens faced hardships during the journey due to hunger and exhaustion. Plague Outbreak: During the process, an outbreak of bubonic plague occurred, affecting both Tughlaq and his soldiers. Revolts and rebellions: Revolts and rebellions further destabilized the sultanate's control over certain regions. Flawed Approach: Historians suggest Tughlaq erred by mass shifting. Moving only the court might have been wiser. Return to Delhi: By 1335, Tughlaq decided to shift the capital back to Delhi due to the deteriorating situation. This allowed citizens to return to their original city.