All certain growth characterlstics distinguish them from other members of the plant kingdom. A) in which B) whom C) whereby D) whose E) that

E) that<br /><br />The correct answer is "that." In this sentence, "that" is used as a relative pronoun to introduce a defining clause, which provides essential information about the "certain growth characteristics" that distinguish them from other members of the plant kingdom. The other options (A, B, C, and D) do not fit grammatically in this context.