The student wants to compare the causes of crown shyness proposed in the two theories. Which choice most effectively uses relevant information from the notes to accomplish this goal?
A
While Jacobs proposes that crown shyness is caused by neighboring tree branches brushing against one another, Ng posits that it occurs when branches detect shade from nearby trees’ branches.
B
Both Jacobs and Ng have proposed theories to explain what causes crown shyness.
C
Ng posits the mutual shade avoidance theory, whereas Jacobs proposes an alternative theory.
D
Jacobs’s mutual abrasion theory proposes that when neighboring trees brush against one another, branches break off, resulting in a phenomenon in which the tops of trees grow close together but don’t overlap.
Explanation
Correct answer: A.
Choice A is the best answer. The sentence compares the two proposed causes of crown shyness, noting the theories’ differences: Jacobs cites branches brushing against one another as the cause, while Ng cites branches detecting shade from other branches as the cause.
Why the other choices are wrong
Choice B
Choice B is incorrect. The sentence merely identifies the existence of two theories for crown shyness; it doesn’t compare the causes proposed by each theory.
Choice C
Choice C is incorrect. The sentence merely indicates that there are two different theories for crown shyness; it doesn’t compare the causes proposed by each theory.
Choice D
Choice D is incorrect. The sentence merely explains one theory for crown shyness; it doesn’t compare two theories.