Why Are So Few Volcanoes Mapped in the Middle of the Oceans

Why are so few volcanoes mapped in the middle of the oceans?

A) The middle of the oceans corresponds with the middle of tectonic plates, so there are only hot-spot volcanoes there.
B) Geologists cannot pinpoint the locations of many recently active seafloor volcanoes.
C) There are only convergent plate boundaries under the ocean, which are less likely to have volcanoes than transform or divergent boundaries.
D) There are only divergent plate boundaries under the ocean, which are less likely to have volcanoes than transform or convergent boundaries.