The ending temperature when combining a cold temperature of 4°C and a hot temperature of 56°C is the midpoint, which is 30°C. Option B is correct.
If we have a cold temperature of 4°C and a hot temperature of 56°C, and we want to find the ending temperature when these two temperatures are somehow combined or averaged, we would calculate the midpoint between these two values.
The midpoint (also known as average temperature) would be calculated by adding the two temperatures together and dividing by two. This gives:
(4°C + 56°C) / 2 = 60°C / 2 = 30°C
Therefore, the ending temperature would be 30°C.
Hence, B. is the correct option.