Which of These Conclusions Is Supported by the Research of Both

Which of these conclusions is supported by the research of both Went and Charles and Francis Darwin on shoot responses to light?

A) When shoots are exposed to light, a chemical substance migrates toward the light.
B) Agar contains a chemical substance that mimics a plant hormone.
C) A chemical substance involved in shoot bending is produced in shoot tips.
D) Once shoot tips have been cut, normal growth cannot be induced.
E) Light stimulates the synthesis of a plant hormone that responds to light.