I do not know how to commence or bring forward my own judgement for this question but there needs to be some understanding before claiming the final answer to be correct. I have seen a lot of people claiming that the final answer is just the opposite and they have to say that the angles are similar but in a reverse direction. But there is always a second option or opinion to every question. For me, it is clear from the figure that there is no question or demand to consider the answers from a clockwise or an anticlockwise direction or pattern.
Hence the answer of the opposite is partly true but it can be certainly from the other way round too. For instance, if you just consider the anticlockwise demand, then there can be a debate that the quantity B is large since the angle makes more than 180 degrees. This can be visually observed from looking at the top of the angle. It certainly makes more than 180 degrees and then you can certainly judge just from rough estimation. But if you look for the same quantity of B from the bottom, the angle appears to be a replica of the quantity A but in the opposite direction.
Hence, in this way you can consider the answer of the other that the angle is opposite to the quantity A. However these are one of the decisions where you can consider the answer to go either way if there is a doubt of the opinion. Hence, when you will be considering the option from the question, you can select from option A and from B but again it has to go with absolute decision making of yours. You can go for B and for A likewise but there needs to be proper reasoning to it. And in these questions, I feel that there is a chance of minor errors that can even come from my side too. Thus, please ensure that you verify and cross check the answers from different sources in addition.