The oldest rocks in the earth's crust were once molten, and came from deep inside the earth. The molten rock, called magma, spewed out in volcanic eruptions during the earth;s early life and solidified into hard rock's called

Question

$\begin{array}{1 1} a.granite \\ b.basalt \\ c.igneous\; rocks \\ d.sedimentary\; rocks \end{array} $