Question

which of the answer choices is not a standard used to prove causation?
two variables must be correlated.
the intervening variable has to be identified and removed.
a change in the independent variable must occur in the dependent can occur.
all possible factors must be taken into account.

Explanation:

To determine the non-standard for proving causation:

1. Correlation between variables is a foundational first step (covariation is required for causation).
2. Identifying and accounting for intervening/confounding variables is a standard to rule out alternative explanations.
3. The requirement that a change in the independent variable precedes a change in the dependent variable (temporal precedence) is a core standard; the option's wording is a misphrased version of this, but it aligns with a causation principle.
4. It is impossible to account for all possible factors in practice, so this is not a standard requirement for proving causation.

Answer:

D. All possible factors must be taken into account.