Answer:
I guess A, I am not sure...
Answer: the valence electron for phosphorus is 5. To achieve an octet electron arrangement, it needs to lose 5 electrons or gain 3 electrons. It is easier to gain 3 electrons than to lose 5 electrons. So phosphorus has to gain 3 electrons.
Explanation:
Hope it helps sorry if it doesn't
The following is produced when propane (C₃H₈) is combusted completely : H₂O
<h3>Further explanation </h3>
Complete combustion of Hydrocarbons with Oxygen will be obtained by CO₂ and H₂O compounds.
If O₂ is insufficient there will be incomplete combustion produced by CO and H and O
Hydrocarbon combustion reactions (especially alkanes) 
For combustion of propane C₃H₈ (n = 3) ⇒ completely(excess O₂) :
C₃H₈+5O₂⇒3CO₂+4H₂O
The products of combustion : CO₂ and H₂O
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