Correct Answer: 100%

Solution : The foreign exchange reserves in 1997–1998 were $5040$ million, as seen in the bar graph.
2520 million was the amount of foreign exchange reserves in 1993–94.
Change in the number of reserves = $5040 - 2520= 2520$
Percentage increase = $\frac{\text{Difference}}{\text{The foreign exchange reserves in 1993–1994}} \times 100$.
= $\frac{2520}{2520}\times 100=100$%
Hence, the correct answer is 100%.