Concept:Use the property logab=c⟹b=ac repeatedly from the outermost logarithm inward.Explanation:We start with log10[log10(log10x)]=0.Since log10(anything)=0 means the argument is 100=1, we get:log10(log10x)=1.Now log10(log10x)=1 implies log10x=101=10.Finally, log10x=10 implies x=1010.Answer:x=1010, which corresponds to option C.