Correct Answer: 1996

Solution : As per the graph,
The production of company Z in the period 1996 = 35 lakh tonnes
The production of company Y in the period 1996 = 25 lakh tonnes
Percentage of production in the period 1996 = $\frac{35}{25}$ × 100 = 140%
The production of company Z in the period 1997 = 40 lakh tonnes
The production of company Y in the period 1997 = 35 lakh tonnes
Percentage of production in the period 1997 = $\frac{40}{35}$ × 100 = 114.29%
The production of company Z in the period 1998 = 45 lakh tonnes
The production of company Y in the period 1998 = 35 lakh tonnes
Percentage of production in the period 1997 = $\frac{45}{35}$ × 100 = 128.57%
The production of company Z in the period 1999 = 35 lakh tonnes
The production of company Y in the period 1999 = 40 lakh tonnes
Percentage of production in the period 1999 = $\frac{35}{40}$ × 100 = 87.5%
The production of company Z in the period 2000 = 35 lakh tonnes
The production of company Y in the period 2000 = 50 lakh tonnes
Percentage of production in the period 2000 = $\frac{35}{50}$ × 100 = 70%
Therefore, the percentage of production of company Z to the production of company Y was maximum in 1996.
Hence, the correct answer is 1996.