The correct answer is option C, that is, hypothesis.
The hypothesis is the starting building block in the scientific method. It is also illustrated as an educated guess, based on previous observation and knowledge. A hypothesis refers to a recommended solution for an unexplained event, which does not fit into the present accepted scientific theory.
The fundamental concept of a hypothesis is that there is no pre-determined result. For a hypothesis to be considered as scientific hypothesis, it has to be something, which can be refuted or supported via carefully crafted observation or experimentation.