A falsifiable theory

A) disagrees with known, replicable data.
B) makes clear, unambiguous predictions.
C) is widely debated and disputed.
D) has not yet been tested.

A falsifiable theory must be able to make clear, unambiguous predictions that can be tested through observation and experimentation. If the theory's predictions are found to be incorrect, then the theory can be falsified. Disagreeing with known, replicable data (A) would make the theory already falsified, and being widely debated and disputed (C) does not necessarily mean that the theory is falsifiable. The fact that a theory has not yet been tested (D) does not provide enough information to determine if it is falsifiable.