Alright, so we have the ocean water freezing point temperature (-2.5 C) and the Antifreeze temperature (-64 C). The temperature is currently at the ocean water freezing temperature (-2.5 C) and we want to find the difference between that and the freezing temperature for Antifreeze (-64 C). Since both numbers are negative, it's OK to make both positive and find the difference between those in this case. Therefore, we need to find the difference between 64 and 2.5, and 64-2.5=61.5 (A)