The elongation of a wire under a load depends on its length, cross-sectional area and the material of the wire. In this case, all four wires are made of the same material, which means that the material`s properties will not be a factor in determining the elongation.

Option 1 and 4 have the same length but different diameters. Since diameter is inversely related to elongation, the wire with less diameter (1 mm in option 4) would elongate more.

Option 2 is longer than option 1 but with the same diameter. As length is directly proportional to elongation, the wire in option 2 would elongate more than option 1.

Option 3 has the longest length and the diameter is less than 2mm of option 1 and 2 but more than 1mm of option 4, resulting in a small cross-sectional area. This wire would elongate maximum due to the combined effect of its length and smaller cross-sectional area, making option 3 the correct answer.