Concept:A logarithm can be rewritten in exponential form: if logab=c, then b=ac.Explanation:Given log2x=10, convert to exponential form: x=210.Given logxy=100, convert to exponential form: y=x100.Substitute x=210 into y=x100: y=(210)100.Apply the power rule (am)n=amn: y=210×100=21000.So the value of y is 21000, which matches option B.Answer:y=21000