When the United States first entered the space race, NASA devised three projects that would develop manned spaceflight in
stages. In chronological order, these projects were Mercury, Gemini, and Apollo. Each project had specific mission goals that were
focused on both immediate and long-term results. Project Mercury focused on preliminary and initial manned spaceflight, with the
overall goal being to establish a well-rehearsed escape and recovery procedure for manned space vehicles. Project Gemini, built
on procedures developed in Project Mercury, focused on establishing the "meat and potatoes of advanced spacecraft operation
such as orbital control maneuvers, spacewalks, and orbital rendezvous and docking. The overall goal of Project Gemini was to
enact a series of techniques that would allow astronaut crews to reach the Moon in relative safety. Finally, Project Apollo, by far the
most ambitious of the three projects, focused on regular visits to the Moon with the goal of capturing research data on
extraterrestrial bodies. All three projects were extremely successful in both immediate and long-term goals.
What organizational method is used to organize this paragraph?
A.
classification
B.
problem solution
C.
cause and effect
D.
compare and contrast