Answer:
D. Mathematical expressions for the relationships
Explanation:
Quantitative analysis also called QA for short is the technique that tries to understand behaviour by using mathematical and statistical modeling, measurement and research. A quantitative analyst aims to represent a given reality in terms of numerical value. This can be achieved by using mathematical formulas and expressions to explain the relationships that exists between the variables. The data analyzed are usually gotten from polls and questionnaires or in general, well structured research instruments.