The best statement that describes Ruby gathering enough evidence to support a scientific explanation concerning plant growth rates is:
**Ruby measures the heights of several species A, B, C, and D plants for a week under the same conditions and finds journal articles that describe the growth rates of each species.**
This option indicates that Ruby is collecting data from multiple species under controlled conditions, which allows for a more reliable comparison. Additionally, referencing journal articles strengthens her investigation by providing scientific backing to her findings.