Questions

BP Kanungo was appointed as Deputy Governor in Reserve Bank of India (RBI) for three years. The Appointments Committee of Cabinet (ACC) has approved his appointment to the post with effect from the date of taking over the charge on or after April 3, an order issued by Personnel Ministry said. He has been appointed in place of R Gandhi, it said.
Kanungo was in March last year appointed as Executive Director in the central bank.

A sentence whose meaning is unclear is called as Ambiguous.

The kidneys are stimulated to produce renin by a decrease in the blood pressure.

The renin-angiotensin system or RAS regulates blood pressure and fluid balance in the body. When blood volume or sodium levels in the body are low, or blood potassium is high, cells in the kidney release the enzyme, renin. Renin's primary function is therefore to eventually cause an increase in blood pressure, leading to restoration of perfusion pressure in the kidneys.

Before transferring the fish, the position is the man with the fish and the bucket of water. After transferring the position is: the man without the fish, but the fish inside the water in the bucket. Thus to know  whether there is any change in weight, it is enough to consider whether there is any change in weight when the fish in air is transferred into the water. The answer is there is no change as when in water though it loses weight due to upthrust of water on it, the level of water increases and exerts an equal force at the bottom.So, (c) is correct.

Manabendra Nath Roy, known as M.N. Roy was an Indian revolutionary, radical activist and political theorist, as well as a noted philosopher in the 20th century. Roy was a founder of the Mexican Communist Party and the Communist Party of India.