This question format Is quite reoccurring with physics test , like they will always ask how 3 or more things are affected given certain conditions . For this I just thought that if reaction time and speed stay the same as the text said , then the thinking distance stays the same as , they are two factors which affect it. For braking distance , I said it decreases due to the ground surface being a hill going upwards , so , it could be rocky and more friction applies to the tyres. Stopping distance is thinking + braking , so if one decreases so does the stopping distance all together.