When Leanne read experimental evidence that indicated orange juice consumption triggers hyperactivity in children, she questioned whether the tested children had been randomly assigned to experimental conditions. Leanne's reaction best illustrates:

critical thinking.

Explanation:

Critical thinking -

It is the method by which a proper analysis of any fact or activity is done before final judgement, is referred to as critical thinking.

In this method, the people tries to refer to every possible aspect of the fcat or activity, to have a wider angle of thinking.

Critical thinking is self-corrective thinking, self-disciplined and self-directed.

Hence, from the given scenario of the question,

The correct term is critical thinking.