The correct answer is: a) Higher transportation costs.
Limited access to cold storage facilities and efficient transportation networks in Bihar can lead to higher transportation costs for agricultural produce. This is because farmers will have to incur additional costs to transport their produce to markets where it can be sold. These costs can include the cost of hiring trucks or other vehicles, the cost of fuel, and the cost of tolls. In addition, farmers may have to pay higher prices for storage facilities if they are unable to store their produce on their own.
The other options are incorrect because they are not directly related to the lack of cold storage facilities and efficient transportation networks in Bihar. Option b, post-harvest losses for agricultural produce, can be caused by a number of factors, including pests, diseases, and weather conditions. Option c, traffic congestion in urban areas, is caused by a number of factors, including the number of vehicles on the road, the layout of the roads, and the number of traffic lights. Option d, shortage of fuel, can be caused by a number of factors, including a lack of refining capacity, a lack of storage capacity, and a lack of transportation infrastructure.