Here's a problem to solve: A lab group investigates the growth rates of four plants grown near a classroom window. The group's conclusion is most strengthened by similar data from which of these sources?

Among the 4 following options, which is the correct answer?

- A: other lab groups investigating the same question
 
- B: average growth rates of the plants published in a book
 
- C: an experiment of different plants in the same environment
 
- D: a new experiment done with larger plants
 