B. It is open to change as new evidence or data is discovered. If scientists discover new evidence, they must modify their theories to conform with the new data.
A. is incorrect. Scientific laws are so well established that there can be no exceptions.
C. is incorrect. A scientific theory is the collective judgement of scientists as to the best explanation for a phenomenon. A new observation may require modification of the theory.
D. is incorrect. Advancements in technology can provide new evidence that requires new explanations.