In most underdeveloped countries, development plans do not achieve their objective due to

Step 1: Analyze the question The question asks for the main reason development plans in underdeveloped countries often fail to achieve their objectives. We are looking for a cause tied to planning and implementation.

Step 2: Explain the concept A development plan is a government's structured programme for achieving economic goals such as growth, employment, and infrastructure. Common reasons for failure in developing countries include:

• Poor implementation and weak coordination between levels of government (federal, state, local)
• Policy inconsistency and changes of government
• Corruption and misappropriation of funds
• Inadequate funds and lack of reliable data
• Shortage of skilled manpower

Step 3: Evaluate the options

• A. Poor coordination between local and national governments: This is a real implementation problem. When different levels of government do not work together, projects are duplicated, abandoned, or poorly funded, so the plan's targets are missed. This fits well.
• B. Exportation of more primary products: Exporting primary products reflects the structure of the economy. It can cause vulnerability to price shocks, but it is not a direct reason why a plan fails, and exporting more does not make a plan fail.
• C. Lack of educational institutions: Many such countries do have schools. The problem is more about quality and funding, so "lack" is too absolute and is not the typical textbook cause.
• D. Urban-rural migration: This is a result of uneven development and can strain cities, but it is not the main reason plans fail.

Step 4: Answer Option A is the best choice. It directly addresses the implementation weakness that undermines development plans.

Tip: For "why do plans fail" questions, look for words like coordination, implementation, corruption, inconsistency, funding. Options that describe economic structure or effects (like B and D) are usually distractors.