Explanation:

- To find the average investment in raw materials from 1997 to 1999, you need data on the amount invested each year.

- Adding these yearly amounts and then dividing by the number of years (in this case, 3) gives the average investment.

- Without specific yearly data, it's challenging to determine the correct answer.

- Option 1: Rs310 lakh

Suggests a lower average investment.

- Option 2: Rs330 lakh

Slightly higher than option 1 but still on the lower side.

- Option 3: Rs400 lakh

Assumes a relatively higher average investment.

- Option 4: Rs410 lakh

Indicates the highest average investment of the options.

Assuming you have the necessary data and calculations: .