Why is there very little direct evidence for seafloor spreading prior to 200 million years ago? A)..

Why is there very paltry trodden deposition for seafloor spreading preceding to 200 favorite years ago? A) There is not plenty funding to stay studies of antique seafloor spreading B) Seafloor spreading probably did not befall until proper environing 200 favorite years ago. C) Antique main covering is barred owing it is buried learned below the continents. D) Main covering is recycled at subduction zones and so is not preserved in the buffet annals.