I believe the answer is C.
There is no set number of "lines" of longitude. You're free
to draw as few or as many 'lines' to mark the 360 degrees
of longitude on the Earth's surface.
However many lines you decide to draw on your map or globe,
they ALL cross the equator.
It helps in a big way because it preserves the land and
replenishes the trees that were cut down.
It also gives animals sanctuary when the new trees grow and most
important of all it prevents erosion and floods that not only destroys the
environment but also endangers man as well.
Hydropower, wind power, solar power.
