The correct answer is - d. shield volcanoes.
The Hawaiian volcanoes are volcanoes that fall into the category of the shield volcanoes. They are slightly dome shaped volcanoes, spread out over a very large area, are not steep, and are volcanoes that tend to not have explosive eruptions as their magma is usually high in silica content.
The volcanoes on Hawaii are volcanoes that have formed over a hot spot, which means that they are not formed at the boundary of the tectonic plates, but instead, they are formed in the middle of the plate.
Mauna Loa and Mauna Kea are actually the biggest volcanoes in the world in the present day.