Option 1: +2-5 Dioptre

This option is incorrect. The format of the answer (+x-y Dioptre) is incorrect. The power of a lens should be expressed as a single positive number with the unit "Dioptre".

Option 2: +3 Dioptre

This option is incorrect. The power of a lens with a focal length of 25 cm cannot be exactly +3 Dioptre. A lens with a focal length of 25 cm has a power of +4 Dioptre, not +3 Dioptre.

Option 3: +4 Dioptre

This is the correct answer. The power of a lens with a focal length of 25 cm is +4 Dioptre. The power of a lens is determined by the formula: Power (P) = 1 / Focal Length (f). In this case, the focal length is 25 cm, so the power is 1 / 25 cm = +4 Dioptre.

Option 4: +5 Dioptre

This option is incorrect. The power of a lens with a focal length of 25 cm is not +5 Dioptre, it is +4 Dioptre.

In conclusion,