The steps in the heating of water in a pot kept on a stove are listed below:

Step 1: Heat from the flame travels to the base of the pot
Step 2: Heat from the base of the pot travels to the water near its base
Step 3: Heat from the water near the base of the pot travels to the upper layers of water

In which steps is heat transferred by conduction?

Step 3
Step 1 and Step 3
Step 1 and Step 2
Step 1, Step 2, and Step 3