The correct option is C Associative Property of Multiplication
Associative property states that no matter how you group the terms in a problem, the answer will remain same.
i.e.
a + (b + c) = (a + b) + c or a (b x c) = (a x b) c
Here √3(√7×√10)=(√3×√7)√10
Hence the given equation illustrates the associative Property of Multiplication.