Suppose little is known about the problem we are trying to solve, but we need to have conclusive answers at the end of the research project. Which of the following could be appropriate order of conducting the research?

$3$ Exploratory Research followed by Descriptive Research

$2$ Exploratory Research followed by Causal Research

$3$ Descriptive Research followed by Causal Research

$4$ Both $(1)$ and $(2)$ would be appropriate, but not $(3)$

$5(1),(2),$ and $(3)$ would be appropriate