Step 1: Identify true characteristics of hypotheses.
- (a) Correct: Hypothesis = tentative proposition, subject to empirical test.
- (b) Correct: Always stated in declarative form, testable via observation/experiment.
- (d) Correct: Hypotheses guide variable selection, operationalisation, and measurement.
Step 2: Spot the incorrect one.
- (c) Wrong because in exploratory research or situations with very little prior knowledge, you may not have enough basis to formulate a hypothesis — you may just explore phenomena.
\[
\boxed{(c)}
\]