What Is the Connection Between the Amount of Silica in a Melt

What is the connection between the amount of silica in a melt and how viscous it is?

A) Higher silica content lowers the melting temperature and since increasing the temperature of a magma decreases viscosity increasing silica content increases viscosity.
B) Silica forms strong bonds, so higher amounts of silica make for more viscous magma.
C) Higher silica content means a larger amount of water a magma can dissolve and water decreases magma viscosity, so increasing silica content decreases magma viscosity.
D) There is no correlation between silica content and magma viscosity.