Step 1: Find the subject of the sentence.
The subject is Neither of the players. The key word is Neither, not players.
Step 2: Recall the rule for Neither.
Neither is treated as singular, so it needs a singular verb.
Step 3: Check the verb used.
The sentence uses were, which is plural. That clashes with singular Neither.
Step 4: Fix it mentally.
The correct form is was willing, not were willing.
Step 5: Confirm the other parts are fine.
to accept and the decision have no grammar problem.
Step 6: State the answer.
The error is in part B, were willing. \[ \boxed{\text{were willing}} \]