Detailed Answer
Answer (C) is correct. Francine will pay fewer dollars for 10,000 Euros in 30 days than paying today. In 30 days, Francine can pay $1.2312 dollars per Euro, but if she were to pay today using the spot rate, she would pay $1.2535 per Euro. The bill is at a fixed price and ignoring interest rates, it is cheaper in dollars for Francine to pay the bill in 30 days. Therefore, the purchasing power of the dollar increases over the next 30 days.