(A): A man is sitting in a boat which is floating on a pond. If the man drinks some water from the pond, the level of the water in the pond decreases.

(R) : According to Archimede's principle the weight displaced by body is equal to the weight of the body

• The boat will sink somewhat as a result of the man's increased weight, replacing the same amount of water he has consumed.
•  As a result, the amount of water in the pond that was elevated equals the amount that was lost when the man drank the water. As a result, the water's level won't alter.
• There is no change in the water's level. The cause is that when a person drinks water (let's say m gm), their weight increases by m gm, and as a result, the amount of water they are displacing increases by m gm, tending to raise the level. 
• This much water has already been ingested by the individual, though. Consequently, the pond's level stays the same.

Hence the correct answer is 'A' is false and 'R' is true.