The sentence makes clear that the timeframe in question is "the past several
years." Since the action began in the past but continues to the present, the
appropriate tense is the present perfect (for example, "have walked", "have eaten",
etc.)
(A) This choice incorrectly uses the conditional tense "would feel," which is
inappropriate here to indicate an actual occurrence.
(B) This choice incorrectly uses the future tense "will feel," which is inconsistent with
the past and present nature of the event.
(C) CORRECT. The present perfect "have felt" correctly indicates that that the
orchestras began to feel the pressure in the past and continue to feel the pressure in
the present.
(D) This choice incorrectly uses the simple present tense "feel," which does not
indicate that the action began in the past and continues to the present.
(E) This choice incorrectly uses the present tense "are feeling," which does not
address the past nature of the sentence.