The hypothesis is defined as forming a possible explanation for a research question. This hypothesis developed from experimental evidence or by observing an event. The theory is going to produce hypothesis that needed to be tested in research.
In case of scientific phenomenon, it is easier to obtain both testable hypotheses because both dependent & independent variables can be easily identified; finally investigator can design a study by reviewing literature review for experimental protocols, previous investigations. This hypothesis is examined by experiment by comparing effects of behaviour of experimental groups with that of control groups. In interview, there are no control groups to compare.
Thus, the options (d), (c) and (b) are incorrect.
The hypothesis is defined as forming a possible explanation for a research question. This hypothesis developed from experimental evidence or by observing an event.
Therefore, the correct option is – a. hypothesis.