I would think that the answer is D. all of these, considering that:
1) The cytoplasm is mostly made of water, but also contains salt, enzymes, organelles, and orgaince molecules; 2) The cytoplasm supports and suspends cellular molecules and organelles; and 3) Chemical reactions also occur in the cytoplasm, and the enzymes it contains help speed up these reactions.
For a family of four, a first aid kit would include scissors. A multi-purpose tool would come handy, but is not necessary. Rubbing alcohol is out of the ordinary, and barbiturates are a type of drug unneeded in a first aid kit.
