Step 1: Understand the historical background of Yeoman.
In medieval England, a Yeoman was a loyal hardworking freeman or attendant in the royal household, renowned for reliable and dedicated service - especially on the battlefield where yeomen were counted on to deliver.
Step 2: Derive the meaning of Yeoman's service.
Drawing on this tradition of faithful, effective help, the idiom "Yeoman's service" evolved to mean exceptionally efficient, useful, and loyal assistance given to someone in need.
Step 3: Match to the correct option.
"Efficient or useful help" is the direct meaning of the idiom; options (2), (3), and (4) suggest minimal, self-serving, or reluctant service - all opposite to the spirit of genuine yeoman service.
\[ \boxed{\text{Efficient or useful help}} \]