13. Questions (13-16): Read the following passage and answer the questions given below:
Raisins are dried grapes that have been eaten for thousands of years. Nearly 3,500 years ago, the first raisins were discovered as grapes that were drying in the sun on a vine. In medieval Europe, raisins were used as sweeteners, medicine, and even as a form of money!
In America, raisins were first grown after an 1873 heat wave in California destroyed its valuable grape crop, leaving only dried, wrinkly, but tasty grapes on the vines. Soon, farmers began developing seedless grapes in California that were thin-skinned and sweet. These grapes would be purposely dried in the sun and became the popular dark raisin we eat and enjoy today. Later, a golden variety of raisin was made by treating grapes with a chemical called sulfur dioxide and using special methods to dry them.
Today, central California remains the center of the world’s raisin industry, producing nearly 95 percent of the world’s raisins. Its green valleys, sunny climate, and hot temperatures provide the perfect conditions for grapes that are dried into raisins.
Which of the following were raisins not used as?