Final answer:
Regression analysis is a diagnostic analysis technique used by geographers to determine the strength and direction of causality between variables.
Step-by-step explanation:
Regression analysis is a diagnostic analysis technique used by geographers to determine the strength and direction of causality between variables. It helps analyze the relationship between a dependent variable and one or more independent variables. Examples of independent variables in geographic studies include factors like ethnicity, income, and access to parks.
Therefore, the correct answer is 'd. microarray analysis' as it does not directly involve hybridization between single-stranded nucleic acid molecules like the other methods but still involves the binding of nucleic acid sequences to DNA oligonucleotides on a microarray chip.