Answer:
4. the foot-in-the-door technique
Step-by-step explanation:
The term "foot-in-the-door technique" is also written as FITD, and is described as one of the "compliance tactic" that is being focused on making an individual get agreed for a bigger request by convincing him or her for a smaller request initially.
Example: As given in the question above, the volunteer agreed Mrs Timmins to put a small one-foot signboard in her yard and after that the next week the volunteer agreed her to put a three-foot-wide signboard on the front lawn.
In the question above, the given statement is an example of the foot-in-the-door technique.