Engineer: Semiplaning monohulls are a new kind of ship that can attain twice the speed of conventional ships. Due to increased fuel needs, transportation will be much more expensive on semiplaning monohulls than on conventional ships. Similarly, travel on jet airplanes was more expensive than travel on other planes at first, but jet airplanes still attracted enough passengers to be profitable, because they offered greater speed and reliability. Semiplaning monohulls offer the same advantages over traditional ships. Thus they will probably be profitable as well. Which one of the following most accurately describes the role played in the engineer's argument by the statement that transportation will be much more expensive on semiplaning monohulls than on traditional ships? ["It draws an analogy between semiplaning monohulls and conventional ships that constitutes an objection to the argument's main conclusion, one that is subsequently rejected by appeal to another analogy.", "It constitutes a potential objection to the argument's main conclusion, but is subsequently countered by an analogy drawn between ships and airplanes.", "It draws a distinction between characteristics of semiplaning monohulls and characteristics of conventional ships that the argument's main conclusion compares to a distinction between types of airplanes.", "It serves as one of two analogies drawn between semiplaning monohulls and jet airplanes, which function together to support the argument's main conclusion."]