ANSWER:
C. asthenosphere
EXPLANATION:
The asthenosphere is the very gooey, mechanically weak and distorting region of the upper mantle of the Earth. It lies underneath the lithosphere, at profundities between around 80 and 200 km (50 and 120 miles) beneath the surface. The asthenosphere is relatively strong, albeit a portion of its areas could be liquid (e.g., beneath mid-sea edges). The lower limit of the asthenosphere isn't very much characterized. The thickness of the asthenosphere depends basically on the temperature. Notwithstanding, the rheology of the asthenosphere likewise relies upon the rate of deformation, which recommends that the asthenosphere could be additionally framed because of a high rate of misshapen. In a few regions, the asthenosphere could reach out as profound as 700 km (430 mi). It is viewed as the source area of mid-sea edge basalt
