Step 1: Sort all six operations by whether the machine has to travel while working. Harvesting machines move down the crop rows, cultivation implements move across the field behind a tractor, and transportation obviously means movement, so (D), (E) and (F) all need mobile power.
Step 2: That leaves irrigation water lifting, winnowing and threshing. A water pump sits fixed at the source, a winnower is set up at one spot in the yard, and a thresher stays parked while crop is fed into it, all driven from a stationary engine or motor through a belt.
Step 3: Since these three operations never require the power unit to travel, they are the stationary power source operations.
\[\boxed{\text{(A), (B) and (C) only}}\]