Final answer:
A scientific theory is a thoroughly tested explanation for observations, not just a single claim that has been tested once. To become a theory, it must be supported by substantial evidence and accepted within the scientific community.
Step-by-step explanation:
The question addresses the nature of scientific theories and whether a theory is simply a claim that has been tested once with completed research. The correct answer is false.
A scientific theory is much more than just a single tested claim. It is an explanation or a set of explanations for observations in the natural world that has been repeatedly tested and supported by numerous experiments and evidence.
To be considered a theory within the scientific community, it requires widespread acceptance and must explain a broad range of phenomena within a coherent framework. Importantly, scientific theories are built upon hypotheses that have been rigorously and continually subjected to empirical testing, and they stand until evidence to the contrary is discovered.