The reaction of two molecules of 1-chlorobenzene with sodium metal in the presence of dry ether to form diphenyl is known as

Fittig reaction

The correct answer is Option (1) → Fittig reaction

When two molecules of chlorobenzene (aryl halide) react with sodium metal in dry ether, they form diphenyl (C₆H₅–C₆H₅).

Reaction: 2 C₆H₅Cl + 2 Na → C₆H₅–C₆H₅ + 2 NaCl

This is called the Fittig reaction (an extension of Wurtz reaction for aryl halides).

Why others are wrong:

• Sandmeyer's reaction: Converts aryl diazonium salts to aryl halides (uses CuCl/HCl, etc.).
• Grignard reagent reaction: Formation or use of RMgX (not this reaction).
• Wurtz reaction: Joins two alkyl halides (e.g., 2 RCl + 2 Na → R–R), not aryl halides.