Verification of truth — essential element of a race: “A race always has which of the following?”

Introduction / Context:
As with similar items (e.g., “run/race must have …”), this checks for an intrinsic defining element. A race is a competition; it must involve opponents/competitors (rivals). Other trappings are optional.

Given Data / Assumptions:

• “Race” here means a competitive event over distance/time.
• Organization level (referee, audience, prizes) can vary widely.

Concept / Approach:
Definitionally, without rivals/competitors there is no contest to be called a race. Therefore “Rivals” is the unique essential element listed.

Step-by-Step Solution:
Check necessity: rivals/competitors = indispensable.Referee, spectators, prize = contingent on event scale and rules.

Verification / Alternative check:
Time-trials and self-paced events still entail competition among entrants (simultaneous or staggered), preserving the “rivals” requirement.

Why Other Options Are Wrong:
They frequently appear but are not essential; informal races may lack all three.

Common Pitfalls:
Equating popular event features with definitional necessities.

Final Answer:
Rivals