Question

what type of volcano has the most gently sloping sides, due to the low viscosity of the basaltic lavas that form them?
mushroom cone
stratovolcanoes
shield volcanoes
cinder cones

Explanation:

Shield volcanoes are formed by low - viscosity basaltic lava flows that spread out over large areas, resulting in gently sloping sides. Mushroom cones are not a standard type of volcano. Stratovolcanoes have steep sides due to explosive eruptions with viscous lava and ash layers. Cinder cones are built from ejected cinders and have steeper slopes compared to shield volcanoes.

Answer:

C. shield volcanoes