In plants,what is the function of $CAM$?

$A$: Tropical plants are more efficient in $CO_2$ utilization.
$R$: $C_3$ plants ensure that $RuBisCO$ functions as carboxylase,minimizing oxygenase activity.

During the $C_{4}$-cycle,the acids formed are:
$I$. Picric acid
$II$. $OAA$ (Oxaloacetic acid)
$III$. Malic acid
$IV$. Aspartic acid
Select the correct option.

In $C_{4}$-plants,the RuBisCO enzyme is present in:

In most plants,stomata open during the day and close at night. What is the exception to this?

Which of the following is a $CAM$ plant?