In presence of high concentration of oxygen, RuBP carboxylase converts RuBP to : 

PGA and phosphoglycolate

The correct answer is Option (4)-PGA and phosphoglycolate

RuBisCO that is the most abundant enzyme in the world is characterised by the fact that its active site can bind to both CO₂ and O₂ – hence the name.

 RuBisCO has a much greater affinity for CO₂ when the CO₂ : O₂ is nearly equal.  This binding is competitive. It is the relative concentration of O₂ and CO₂ that determines which of the two will bind to the enzyme.

In C3 plants some O₂ does bind to RuBisCO, and hence CO₂ fixation is decreased. Here the RuBP instead of being converted to 2 molecules of PGA binds with O₂ to form one molecule of phosphoglycerate and phosphoglycolate (2 Carbon) in a pathway called photorespiration.

In the photorespiratory pathway, there is neither synthesis of sugars, nor of ATP. Rather it results in the release of CO₂ with the utilisation of ATP. In the photorespiratory pathway there is no synthesis of ATP or NADPH. The biological function of photorespiration is not known yet.

In C4 plants photorespiration does not occur. This is because they have a mechanism that increases the concentration of CO₂ at the enzyme site. This takes place when the C4 acid from the mesophyll is broken down in the bundle sheath cells to release CO₂ – this results in increasing the intracellular concentration of CO₂ .

In turn, this ensures that the RuBisCO functions as a carboxylase minimising the oxygenase activity.  The C4 plants lack photorespiration, you probably can understand why productivity and yields are better in these plants. In addition these plants show tolerance to higher temperatures.