In the Classic Work of Dan Janzen and Acacia Trees

In the classic work of Dan Janzen and acacia trees, Janzen supported his contention that ants were critical to the survival and growth of acacia trees with a variety of data and observations. Which of the following was NOT evidence of Janzen's contention?

A) Trees with ants had fewer herbaceous insects as compared to trees without ants.
B) Trees with ants tend to be heavier than trees without ants.
C) Trees with ants produced more flowers that lasted longer than trees without ants.
D) Trees with ants had higher comparative survival rates than trees without ants.