How long does it usually take for a rock to be transformed from one rock type into another?
a.
a few days
b.
from 300 to 400 years
c.
about one thousand years
d.
thousands to millions of years

D thousands to millions of years because The erosion of rocks takes really long.

For example: The waves attack the headland and then over a course of millions of years it transforms into a cave, then an arch, next a stack and lastly a stump.

Apart from erosion rock transformation can be affected by weathering.

I hope I've helped, I'm studying it in Geography in school at the moment so I'm pretty sure it's correct! ☺

can you elaborate on what the question asks?