The correct answer is option 4 - high melting point. Tungsten is used for the construction of filament in electric bulbs because it has a very high melting point compared to other metals. The filament in a bulb gets extremely hot when electricity passes through it, and this high temperature is necessary for the bulb to emit light. Tungsten can withstand such high temperatures without melting or deforming, making it an ideal choice for the filament material.

Option 1 - high specific resistance, is not the correct answer. While tungsten does have a relatively high specific resistance, it is not the primary reason for its use in electric bulb filaments.

Option 2 - low specific resistance, is incorrect. Tungsten actually has a relatively high specific resistance, as mentioned before.

Option 3 - high light emitting power, is also incorrect. The light emitting power of a bulb is not determined solely by the material of the filament, but also by the design and efficiency of the bulb itself.

Therefore, the correct reason for using tungsten in electric bulb filaments is its high melting point.