Step 1: Understanding the Concept:
Extension communication models analyze how messages flow from information sources to recipients through different channels to achieve desired impacts.
Step 2: Detailed Explanation:
Lasswell's model of communication (formulated by Harold Lasswell in 1948) is a classic verbal model of mass communication.
It is expressed as:
"Who (sender) \(\rightarrow\) Says What (message) \(\rightarrow\) In Which Channel (medium) \(\rightarrow\) To Whom (receiver) \(\rightarrow\) With What Effect (impact)?"
This model is highly useful in agricultural extension for designing mass-media campaigns.
Step 3: Final Answer:
Lasswell's model is associated with mass communication, corresponding to option (D).