Which one of the following selections includes only organic compounds

All organic compounds contain carbon but must contain one or more of the following and nothing else: hydrogen, oxygen, and nitrogen atoms.
Certain amino acids also have sulfur atoms, phosphorus, or other trace elements such as iron or copper.
Here's what my teacher told me to know if it is a organic compound,
C+ PHONS
CARBON+ PHOSPHORUS, HYDROGEN, OXYGEN, NITROGEN, SULFUR
Organic compounds will include things like the nucleic acids, found in DNA, lipids and fatty acids found in the cells of living organisms, proteins and enzymes that are necessary for cellular processes to take place, and more. Meanwhile, inorganic compounds include the salts, metals, and other elemental compounds.
1st: proteins and water
Proteins=> organic
H2O=> no carbon, inorganic
2nd: glucose and DNA
Glucose contains six carbon atoms, 12 hydrogen atoms and six oxygen atoms, which makes it and any other carbohydrate an organic compound.
DNA=> organic
3rd: CO2 and H2O
CARBON and OXYGEN => organic
HYDROGEN AND OXYGEN => not
4th: fat and salts
Fat is organic, there are organic salts but salts in general is inorganic
The answer is #2: glucose and DNA

Spherical shaped cell might increase the surface area and decrease the volume.