Step 1: Understanding the Concept:
Due to environmental persistence and toxicity, DDT use was limited, leading to the use of alternative insecticides.
Step 2: Key Formula or Approach:
Identify known insecticides from the options.
Step 3: Detailed Explanation:
BHC (Benzene Hexachloride), specifically its gamma isomer known as Lindane or Gammexane, is a powerful insecticide used as a replacement for DDT in various agricultural and domestic applications.
CHCl$_3$ and CH$_2$Cl$_2$ are common solvents. Picric acid is an explosive.
Step 4: Final Answer:
BHC is used instead of DDT.