Select the best set of reagents for the following synthesis. 

• A. 1) NaNH₂, NH₃    2) H⁺, H₂O    3) NaNO₂/HCl;    4) NaCN/DMSO;      5) CH₃I;       6) Br₂/hν
• B. 1) NaNH₂, NH₃    2) H⁺, H₂O    3) NaNO₂/HCl;    4) H₃O⁺;      5) NaOH;      6) CH₃CH₂CH₂Br
• C. 1) NaNH₂, NH₃    2) H⁺, H₂O    3) NaNO₂/HCl;    4) HBF₄;     5) CH₃I;       6) Br₂/hν
• D. 1) NaNH₂, NH₃    2) H⁺, H₂O    3) NaNO₂/HCl;    4) H₃O⁺;     5) H₃PO₃;      6) CH₃CH₂CH₂Br

Answer: (B)

Verified step by step guidance

1. Identify the starting material and the target molecule. The starting material is pyridine, and the target molecule is 3-propoxy pyridine.
2. Recognize that the transformation involves the introduction of a propoxy group at the 3-position of pyridine.
3. Consider the use of NaNH2 in NH3 to deprotonate the pyridine, generating a nucleophilic pyridine anion.
4. Use H+, H2O to quench the reaction and stabilize the intermediate.
5. Introduce NaNO2/HCl to form a diazonium salt, which can be further reacted to introduce the desired propoxy group.
6. React the diazonium salt with CH3CH2CH2Br to introduce the propoxy group at the 3-position, completing the synthesis of 3-propoxy pyridine.