What represents a round of golf?

A round of golf is commonly defined as playing a full course, which, in most cases, consists of 18 holes. The correct choice captures the essence of this definition by recognizing that playing 18 holes completes a full golf round according to standard golfing practices. While it is possible to complete a round by playing only 9 holes, particularly in certain formats or to accommodate time constraints, the general understanding and expectation within the sport is that a traditional round consists of 18 holes.

The alternative options do not align with the standard definition. Playing more than 18 holes in a single round is unusual, as it typically exceeds what is considered a full round. Similarly, playing only through the first 3 holes does not fulfill the requirement of completing a round. Likewise, while playing 9 holes is a valid golf activity, it is usually viewed as a half-round rather than a full round.