The T. urticae mite is an agricultural pest that feeds on many crop

­The T. urticae mite is an agricultural pest that feeds on many crop plants, including tomatoes. Some tomato farmers manage this threat by introducing the G. occidentalis mite, a predator of T. urticae. Other tomato farmers spray their crops with miticide, killing all mites within the area that is sprayed.

If the statements above are true, which of the following must be true?

(A) Only if G. occidentalis has first been introduced into a tomato field will spraying with miticide eliminate all T. urticae from the field.
(B) The introduction of G. occidentalis and spraying with miticide are the only two known methods for controlling an outbreak of T. urticae on a tomato farm.
(C) If live N. californicus mites are found in a field that has been sprayed with miticide, these mites entered the field sometime after the field was sprayed.
(D) T. urticae causes more economic damage to tomato farmers than it does to growers of any other major crop plant.
(E) Some tomato farmers have tried both introduction of G. occidentalis and spraying with miticide as ways of managing the threat posed by T. urticae.