How can the following compounds be distinguished using only the techniques listed below and no other information?
a. using proton NMR spectroscopy
b. using ¹³C NMR with DEPT experiments.
c. using Infrared spectroscopy

• A. a. (I) sharp singlet δ 9-10, methyl protons δ 3.7-3.8
  (II) broad singlet δ 10-14, methyl protons δ 2.4
  (III) broad singlet δ 9-10, methyl protons δ 3.7-3.8
  b. (I) C=O around δ 190
  (II) and (III) C=O around δ 170
  c. (I) C—H at 2710 cm⁻¹
  (II) COOH from 2500-3500 cm⁻¹
  (III) OH at 3100-3500 cm⁻¹
• B. a. (I) broad triplet δ 9-10, methyl protons δ 3.7-3.8
  (II) sharp singlet δ 10-14, methyl protons δ 2.4
  (III) broad singlet δ 9-10, methyl protons δ 3.7-3.8
  b. (I) C=O around δ 100
  (II) and (III) C=O around δ 170
  c. (I) C—H at 2710 cm⁻¹
  (II) COOH from 2500-3500 cm⁻¹
  (III) OH at 3100-3500 cm⁻¹
• C. a. (I) broad singlet δ 9-10, methyl protons δ 1.7-1.8
  (II) sharp doublet δ 10-14, methyl protons δ 2.4
  (III) broad singlet δ 9-10, methyl protons δ 3.7-3.8
  b. (I) C=O around δ 190
  (II) and (III) C=O around δ 170
  c. (I) C—H at 2500 cm⁻¹
  (II) COOH from 2000-3000 cm⁻¹
  (III) OH at 3100-3500 cm⁻¹
• D. a. (I) sharp singlet δ 4-5, methyl protons δ 9.0-9.8
  (II) broad singlet δ 7-8, methyl protons δ 2.4
  (III) broad singlet δ 9-10, methyl protons δ 57-5.8
  b. (I) C=O around δ 100
  (II) and (III) C=O around δ 170
  c. (I) C—H at 2710 cm⁻¹
  (II) COOH from 1500-2500 cm⁻¹
  (III) OH at 2100-2600 cm⁻¹

Answer: (A)