Question Optons:
a) directionality problem
b) third-variable problem
c) extreneous variable problem
d) manipulation problem check
Answer: THIRD VARIABLE PROBLEM
Explanation: Third variable problem can be defined as a process whereby an apparent association between an exposure and an outcome is explained by another factor in which the third variable leads to a mistaken causal relationship between two others.
The three variables here are, children; sugar; metabolism. Originally the research was linked to only the children and sugar then later on, a third variable, that lead to a mistaken casual relationship, metabolism came into place.