Barium :

with +2 being the charge
Oxygen :

with -2 being the charge
The given equation can be written as:
Ba + O = BaO
Since the sum charges of Barium and Oxygen equals 0, there is no need to add subscripts.
Both Ba and O appear on the left and right side of the equation once, so there is no need to add a coefficient.
Ba + O = BaO is balanced
Is that Lr? I'm not sure what the L one stand for?
2:1:1:2
Answer: Transpiration---A
Explanation: Transpiration is the process in the water cycle whereby plant loose(excess) water by evaporation through the stomata of their leaves since not all water absorbed by the root is actually used for growth in plants.In order to allow the intake of carbon-dioxide, water must exit the leaves through transpiration which then provides the plant with cooling, rigidity and maintaining the overall water balance of the plant.
I believe that the answer is A i could be wrong though.
By showing what resources the planet had to offer