The correct option is 1, 2 and 4 only regarding the MPLADS. The Members of Parliament Local Area Development Scheme (MPLADS) is designed to ensure that MPs utilize their funds towards creating durable physical infrastructure aimed at public welfare, particularly in health and education sectors (Statement 1). It mandates that a portion of these funds be earmarked for projects benefiting Scheduled Castes (SC) and Scheduled Tribes (ST) to promote equity (Statement 2). Additionally, the requirement for district authorities to inspect at least 10% of the work annually ensures transparency and accountability in the utilization of these funds (Statement 4). However, MPLADS funds can be carried forward beyond the year, making Statement 3 incorrect in this context. This understanding is crucial for UPSC aspirants as it underlines the government's commitment to local development and social equity while emphasizing the importance of monitoring public expenditure.