Eukaryotic cells contain membrane-bound organelles, including a nucleus. Eukaryotes can be single-celled or multi-celled, such as you, me, plants, fungi, and insects. Bacteria are an example of prokaryotes. Prokaryotic cells do not contain a nucleus or any other membrane-bound organelle.
I think the correct answer from the choices listed above is option C/ One reason that a product does not always form is due to unfavorable geometry of the reactants involved. When the geometry is not good for substances to react then no reaction can occur although there is enough energy present.
