Which of the Following Statements Is NOT a Reason That

Which of the following statements is NOT a reason that conifers are absent from the tropics and are seemingly restricted to more temperate, cooler regions?

A) Conifers' single-celled tracheids cannot support large levels of transpiration, whereas those of angiosperms can.
B) Conifer pollination was not as effective in the tropics, because their populations became fragmented by angiosperm competition.
C) In colder regions, the dangers of cavitation due to freezing restrict angiosperm growth.
D) In drier regions, the dangers of cavitation due to drought restrict conifer growth.