Answer:
3- gamma radiation
Explanation:
Hello,
In the above question, 4 of the options are related to polymerization which are
1. Synthetic polymer
2. Natural polymer
3. Condensation polymerization
4. Addition polymerization.
The first two options are types of polymer that exists while the last two are polymerization techniques.
The odd option here which is "gamma radiation" is a particle which is emitted from radioactive substances during decay. It has no mass and no charge but it is highly penetrating and dangerous to human health.
However,
Synthetic polymers are also known as man made polymers and they exist around us because they're present in materials which we use everyday. An example is polyethylene, nylon-6,6 etc
Natural polymers are compounds which are polymeric in nature (compounds catenating to form a complex molecule). Natrual occurring polymers can be found in proteins and some lipids.