Which of the bases given below are able to deprotonate propanoic acid (pK_a = 4.88) in an acid-base reaction that favors the formation of products?
(i) CH₃O⁻ (pK_a of CH₃OH = 15.9)
(ii) NH₃ (pK_a of NH₄⁺ = 9.4)
(iii) CH₃C≡C⁻ (pK_a of CH₃C≡CH = 25)(iv) CH₃CH₂OH (pK_a of CH₃CH₂OH₂⁺ = −2.5)
(v) H₂O (pK_a of H₃O⁺ = −1.7)
(vi) Br⁻ (pK_a of HBr = −9)

• A. (i), (ii), (iii), (iv), (v) and (vi)
• B. (i), (ii), (ii) and (vi)
• C. (i), (iii), (v) and (vi)
• D. (i), (ii) and (iii)

Answer: (D)