Methods of preparation of propane
Simple carboxylic acid or carboxylate ions (like CH3CH2CH2COO–) do not undergo decarboxylation to yield corresponding alkanes because in this case the leaving group would be a carbanion (in this case CH3CH2CH2–) which is very strong base and hence a very poor leaving group (the reason behind this is that strong base wants to give electrons, but leaving group has to take electrons and leave the compound, strong base is poor leaving group and weak base is good leaving group)

For decarboxylation to happen a keto group must exist to stabilise the negative charge, which is not present in salt of butanoic acid CH3CH2CH2COO–Na+



Yield of propane is very less if you chose decarboxylation, that is why Corey-House synthesis is best for preparation of propane.

I want to know why do you think that Option D is correct, mention in comment.