題目：
If, for any reason, you are not satisfied, simply return your purchase with your receipt for an exchange or refund within 90 days when ______ on your Sears Card or Sears Gift Card.
A) purchase
B) purchasing
C) purchased
D) purchases
答案：C
想問版友，選C是因為分詞構句選pp表被動嗎（因為卡片是被購買的）
謝謝