Can someone me with this question because i'm stuck

Which type of scientific statement is defined as a hypothesis or group of hypotheses that can be accepted as true based on the repeated experimentation with similar results

The large increase in atmospheric carbon dioxide in the last 50 years most likely comes from a. an increase in cellular respiration b. increased decomposition by bacteria c. an increase in the burning of fossil fuels d. an increase in photosynthesis

Speed is the ratio of the distance of an object moves to