See image — AITS & Test Series Chemistry Question

💡 Solution & Explanation

X X X X X X X + + 2x2 x2 (one monosubstituted) (three disubstituted) NH BH BH NH HN HB NH BH B NH HN HB X N BH B NH HN HB X X NH B B NH NH BH X X N BH BH N NH BH X X + + x2 NH BH B NH HN HB X + NH BH B N NH BH X X + (Two mono substituted) four disubstituted isomers 2x2