The answer is Na < Cl
Chlorine is more electronegative than sodium because this follows the trend of the periodic table. The trend states that an element's electronegativity increases from left to right of a period and bottom to up of a group. Since sodium and chlorine are from the same period, and chlorine is at the right of sodium, chlorine is more electronegative.
The answer is C: A surfer rides back to the beach on his surf board.
All the others are examples of people doing stuff to the water, C is an example of the water moving something, in this case the water is moving a surfer and his surf board.
