In which layer of earths interior is the temperature the highest?

Earth's inner core , the temperature is about 5700ºK (5400 °C)

This is what i found on google “phytoplankton, tiny organisms that live in the ocean, are autotrophs. some types of bacteria are autotrophs. most autotrophs use a process called photosynthesis to make their food.” i hope this you for what your looking for