a. orange
Red roses, as symbols of passionate love, are among the most common gifts on Valentines Day. The reason you don't see many yellow roses in Valentines bouquets is because they are typically given to express friendship.
As a symbol of pride, orange roses are popular gifts for graduations. But pride isn't the only emotion orange roses can convey. As a transitional color between yellow and red, orange can also indicate the a change of heart from friendship to more romantic feelings.
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