Lets read each sentence and determine which one has an opinion in it.
1) Thomas Paine believed that reconoiliation with Britain was no longer possible. This can be proved because others beliefs are sometimes said aloud or conveyed in such a way they can be proven true.
2) Reconciliation had been attempted and had failed. This can be proven aswell.
3) It was unfortunate that Paine called for action. You cannot proove that this was unfortunate. This is most likely the answer.
4) He urged the colonists to take up arms against the British. This is clearly a fact, there is proof somewhere that this happened.
Your best option here is 3. You cannot prove that it was unfortunate from every perspective possible.