Pick out the wrong statement.

• Dehydration of ammonium carbamate to produce urea is endothermic.
• Direct use of liquid ammonia as a fertiliser for a tropical country like India is suitable.
• Gypsum (CaSO4. 2H2O) is obtained as a by-product in the wet process for manufacture of ortho-phosphoric acid.
• Phosphate rock when reacted with dilute H2SO4 produces superphosphate.