One can only hold 2 electrons which only means shell two can hold 8, and for the first eighteen elements shell three can hold a maximum of eight electrons
I think its c because solid,liquid nor plasma really fits to the description and i don't really know the last one so the best option is probably C.
The unsaturated zone is the portion of the subsurface above the groundwater table. The soil and rock in this zone contains air as well as water in its pores. ... Unlike the aquifers of the saturated zone below, the unsaturated zone is not a source of readily available water for human consumption
NaHCO3 is the right answer
