Final answer:
Option 2, (CH₃)₂CClCH₂CH₃, is the tertiary alkyl halide because the carbon bonded to chlorine is connected to three other carbon atoms.
Step-by-step explanation:
To determine which of the given compounds is a tertiary alkyl halide, we need to identify the compound in which the halogen atom is attached to a carbon atom that itself is attached to three other carbon atoms. Here are the structures with halogen positions (Cl) analyzed:
Therefore, the correct answer is option 2: (CH₃)₂CClCH₂CH₃. This compound is a tertiary alkyl halide because the carbon bonded to chlorine is connected to three other carbon atoms.