Answer:
It is a theory because it was developed with many new experiments, and it explained the observations.
Step-by-step explanation:
A scientific theory is a term in science that serves as a description and explanation to the manifestation of occurrence of events. It involves fully assessed justification for a set of observations or empirical findings.
Hence, in this case, the correct answer is: "It is a theory because it was developed with many new experiments, and it explained the observations."