Polymerization Type from Repeat Unit Structure

Steps:

• Examine the repeat unit for functional groups and linkages.
• Check if the unit matches a simple alkene-derived chain without ester or amide bonds.
• Confirm no small molecule (e.g., water) elimination is indicated.
• Match to addition process where monomers link directly.

Why A is correct:

• Addition polymerization forms chains by opening double bonds in monomers like alkenes, retaining all atoms in the repeat unit without by-product loss, as per the mechanism of free radical or ionic initiation.

Why the others are wrong:

• B: Condensation involves linking with elimination of water or similar, not matching a simple carbon chain repeat unit.
• C: Incorrect monomer pairing, as the structure derives from a specific alkene, not the one listed.
• D: Wrong for both monomer and type, since no functional groups suggest condensation.

Final answer: A