The correct answer is option 3: 25,000 km.

To understand this, we need to know that the circumference of a circle is the distance around its outer edge. The Earth is roughly spherical in shape, so to find its approximate circumference, we can imagine drawing a circle around it.

Option 1: 13,000 km - This is too small to be the circumference of the Earth. It would mean that the Earth is much smaller than it actually is.

Option 2: 20,000 km - This is also too small. It would still underestimate the Earth`s circumference.

Option 3: 25,000 km - This is the correct answer. It is a reasonable approximation of the Earth`s circumference.

Option 4: 30,000 km - This is too large. It would overestimate the Earth`s circumference.

Therefore, option 3 is the most accurate estimate of the Earth`s circumference among the given options.