Final answer:
Rhyolitic magma has the highest silica concentration.
Step-by-step explanation:
The magma composition with the highest silica concentration is rhyolitic magma. Rhyolitic magma is rich in silica and has a high viscosity, which makes it thick and slow-moving when erupted. Rhyolitic magma is associated with felsic igneous rocks like granite and rhyolite.
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