A teacher takes the turntable out of a microwave oven and puts a bar of chocolate inside the oven. She then turns the oven on for a brief period. A stationary wave is produced inside the oven. After the chocolate is taken out, the teacher notices two small melted regions of chocolate $6.0\,\text{cm}$ apart, with chocolate that has not melted between them. Each melted region is positioned at an antinode. Assume that the microwaves travel at $3.0 \times 10^8\,\text{m s}^{-1}$. What is the frequency of the microwaves emitted by the oven?
- A$25\,\text{MHz}$
- B$50\,\text{MHz}$
- C$2.5\,\text{GHz}$
- D$5.0\,\text{GHz}$