Questions

Water has the maximum density at 4oC. So at this temperature, it sinks down to bottom and stays here. If it cools further, it will become less dense and move up. So while the upper layers can cool enough to form ice, the bottom layers remain as water at  4oC .  

Therefore, (C) is correct.

The Rolling plan refers to one-year plans in the five-year perspective. under Rolling plan, there would be an annual appraisal of the progress of the plan and on the basis of such an appraisal, the plan for the next year will be prepared. The plan would go on rolling year after year.

The process of conversion of milk into curd is called fermentation.  It is a chemical change. Milk consists of globular proteins called casein. As the microorganism lactobacillus react with milk and turn it to curd. For it 37 degree temperature is needed. But sometimes when it does not get favourable condition, then other microorganism react and makes the curd taste different.

Answer A is incorrect because the WBS hierarchy does not prevent duplication by itself. Answer C is incorrect because a WBS is focused on deliverables and components or work packages and not on tasks. Answer D is incorrect because a WBS can be sized appropriately to the project size with as many levels as necessary.