Termination steps include alkyl radical + Br• → alkyl bromide

Steps:

• Identify radicals in propane bromination: primary (CH3CH2CH2•) and secondary ((CH3)2CH•) from C-H abstraction.
• Recall termination steps: radical-radical combinations like R• + R• → R-R or R• + Br• → RBr.
• For R• + Br•, product is alkyl bromide like CH3CH2CH2Br from primary radical.
• Confirm no propagation produces termination products; RBr forms in propagation but also terminates via R• + Br•.

Why C is correct:

• CH3CH2CH2Br forms directly from CH3CH2CH2• + Br•, a termination step consuming two radicals per radical chain mechanism definition.

Why the others are wrong:

• A: CH3CH2CH2CH2Br requires butane substrate, not propane.
• B: CH3CH2CH2CH3 (butane) from two ethyl radicals, irrelevant to propane.
• D: CH3CH2CH2CH3 duplicates B; not a propane-derived termination product.

Final answer: C