The first transcontinental railroad in the united states connected 1. omaha and sacramento2. the great lakes and new orleans3. new york and chicago4. chicago and los angeles

a and b because with the other three, they simplify to something else.

radiative zone

explanation    

radiative zone is the layer of the sun which energy is transferred away from the core by radiation. although, the core is the only part of the sun that produces an appreciable amount of heat through fusion. in fact, 99% of the energy produced by the sun takes place within 24% of the sun's radius.