Henry the doctor is trying to administer an antidote to his patient. the antidote needs to pass through the membrane of his patient's cell walls. he has 4 versions of the antidote. serum a is in gas form, serum b contains polar organic molecules, serum c contains ions and serum d contains macromolecules. which serum will have the highest rate of diffusion across the patient's cellular membrane and will save the patient's life the fastest?