Which group contains elements composed of diatomic molecules at stp

Determine the mass of fuel required for the expected energy consumption in the united states for the next ten years. energy use per person per year in the united states = 3.5 x 1011joules base calculations on current population of 310,000,000.

The crust of earth may a- continets and ocean floors. b-continents only. c-layers of sedimentary rocks and continents. d-all of the above

The answer for #3 is c but i don't know why