PTFE structural unit: which formula best represents the repeating unit/monomer basis associated with PTFE production?

Introduction / Context:
PTFE (polytetrafluoroethylene) is produced from tetrafluoroethylene (TFE). Many questions refer to the monomer form when asking about the “repeating unit”; being able to identify the right formula avoids confusion.

Given Data / Assumptions:

• The monomer for PTFE is tetrafluoroethylene: F2C=CF2.
• The polymer backbone repeat is –CF2–CF2– derived from TFE.

Concept / Approach:
When options list small molecular formulae, choose the correct monomer TFE for PTFE production. Alternatives such as chloro or fully substituted CF3 units do not match PTFE chemistry.

Step-by-Step Solution:
Identify the PTFE monomer: F2C=CF2.Map it to the polymer repeat –CF2–CF2–.

Final Answer:
F2C=CF2