Na is cation so it loses electron to be positive and become stable losing one valence shells one electron so it's oxidation number is +1 ie A is correct
I think you add 29.57 + 80 and the answer would be 30.37
1 km is equal to 100,000 cm
and you need to divide it to 1 km so that you can get rid of the km.
Using P1V1/T1 = P2V2/T2, 1 being the conditions initially and 2 being the secondary conditions…. always make sure you convert you units first , L=695.8262L