Pick out the correct statement.

Reaction of NH$3$ with HNO$3$ to produce $($NH$4)2$NO$3$ is endothermic

With increase in NH$3/$CO$2$ ratio, urea yield decreases for a given temperature, pressure and total feed rate

Biuret $($an intermediate during urea manufacture$)$ is toxic to seeds and animals

Both $($B$)$ and $($C$)$