Nine-year-old Sochi is studying weather differences in the United States. She learns that it rains more in Hawaii than it does in Washington and more in Washington than it does in Oregon. Therefore, she concludes that it rains more in Hawaii than it does in Washington and Oregon.
Which concrete-operational principle is Sochi demonstrating?

a) Transitivity
b) Reversibility
c) Conservation
d) Seriation

a) Transitivity                                      

Explanation:

Transitivity: In psychology, the term "transitivity" is described as one of the principles associated with the concrete-operational stage which is considered as one of the different stages of the cognitive development theory and was given by a famous psychologist named Jean Piaget.

Transitivity is considered as an important aspect of the concrete-operational stage and is referred to as an individual's capability to recognize relationships between different things in a "serial order".

In the question above, the given statement represents that Sochi is demonstrating transitivity.