The correct answer is D. impracticability.
Feasibility is the quality of being practicable or capable of being done. In the context of a project, feasibility refers to the likelihood that the project can be completed successfully. A project is considered feasible if it is technically possible, financially viable, and has the support of the necessary stakeholders.
Unsuitability refers to the quality of not being suitable or appropriate for a particular purpose. Cheapness refers to the quality of being low in price. Impropriety refers to the quality of being improper or unethical.
In the context of the question, impracticability is the most likely answer because it is the only option that directly relates to the feasibility of the project. The other options are not relevant to the question.