Answer: a. Latitude
Step-by-step explanation:
The average temperature of ocean's surface is about 17°C. The temperature varies with the seasons and location of the ocean. It means the time of the year -whether it is winters , summers, autumn or spring and location - in which zone it lies.
In winters the temperature dips down. The arctic ocean and Antarctic ocean have extremely low temperatures. On the other ocean lying near equator have higher temperature.
Thus, the ocean’s surface temperatures vary with time of year and a. latitude.