The c does, and it has no choice. An English c placed before e, i or y is soft and says s: city, cent, cycle. Before a, o or u it is hard and says k: cat, cot, cut. Citrange has an i in second position, so the c is soft, and the s spelling is redundant. The rule comes from Latin by way of French and it holds across the whole citrus vocabulary, which is why citron, citric and citrus all begin the same way.