Correct Answer: 4 years

Solution : As per the given bar graph in question,
Total production of fertilizers from 1995-2002 = 25 + 40 + 60 + 45 + 65 + 50 + 75 + 80 = 440 tonnes (in 10000 tonnes)
Total number of given years = 8
$\therefore$ Average production = $\frac{\text{Total production of fertilizers years from 1995-2002}}{\text{Total number of given years}}=\frac{440}{8}$ tonnes = 55 tonnes (in 10000 tonnes)
$\therefore$ Required years = 1997, 1999, 2001, and 2002 (4 years)
Hence, the correct answer is 4 years.