Answer:
Option (D)
Step-by-step explanation:
The seafloor spreading refer to the condition where the lithospheric plates move away from one another. This results in the addition of new materials along the mid oceanic ridge. If this continues at a greater rate in comparison to the rate of subduction then it results in the expansion of the earth's surface, making the earth grow larger.
But in nature, this rate of spreading is balanced by the rate of subduction. This is how the plate motion works on earth.
Thus, the correct answer is option (D).