Excess fertilizer can have negative effects on plants, especially if applied without sufficient water. Option 1 states that the plant will be stunted in growth. This is a possible outcome as excessive fertilizer can lead to imbalances in nutrients, causing growth abnormalities. Therefore, option 1 is a valid choice.

Option 2 suggests that the plant will develop modifications in response to the excess fertilizer. While some plants may exhibit adaptive changes, such as increased root growth or thicker leaves, this option is too vague. Without specifying what kind of modifications will occur, option 2 is not a comprehensive answer.

Option 3 states that the plant will die due to plasmolysis. Plasmolysis occurs when water is extracted from the plant cells, causing them to shrink and possibly leading to plant death. This is a possible consequence of excess fertilizer without water, making option 3 a correct answer.

Option 4 suggests that the plant will remain unaffected. This is incorrect because excess fertilizer without water can cause detrimental effects and potentially harm or kill the plant. Therefore, option 4 is an incorrect choice.

In conclusion, option 3 is the correct answer as excess fertilizer without water can lead to plant death due to plasmolysis.