Polyalkenes lack reactive double bonds Steps:

• Identify polyalkenes as addition polymers from alkene monomers, forming long chains of single C-C bonds (saturated).
• Test statement A: Saturated hydrocarbons do not undergo electrophilic addition with Br₂ without UV light or catalysts.
• Test statement B: Complete combustion of polyalkenes (CₙH₂ₙ₊₂-like) yields only CO₂ and H₂O, standard products not classified as harmful.
• Test statement C: While slow, some polyalkenes biodegrade under specific conditions; "do not readily" overstates inertness.

Why A is correct:

• Polyalkenes have no C=C bonds, so they do not react with Br₂ in the dark via addition (unlike alkenes, per Markovnikov's rule).

Why the others are wrong:

• B: Combustion produces non-toxic CO₂ and H₂O in ideal conditions; "harmful products" implies pollutants like those from halogenated polymers.
• C: Polyalkenes degrade slowly via oxidation or microbial action but do so eventually; statement ignores partial biodegradability.

Final answer: A