Which of the following statements about the polarity of the R groups, their respective acidity or basicity, and hydrophobicity or hydrophilicity are correct?
I) Amino acids with nonpolar, aliphatic R groups are generally hydrophobic and do not significantly affect the acidity or basicity of the amino acid.
II) Amino acids with polar, uncharged R groups are hydrophilic and can participate in hydrogen bonding, but they do not influence the overall charge of the amino acid.
III) Amino acids with acidic R groups are hydrophobic due to their negative charge, which repels water molecules.
IV) Amino acids with basic R groups are generally hydrophilic and positively charged, making them soluble in water.
V) Aromatic amino acids with hydrophobic rings are always neutral in terms of charge and do not participate in hydrogen bonding.

• A. I, II, and III
• B. I, II, and IV
• C. III and IV
• D. II and IV

Answer: (B)