The incorrectly spelled word in the given sentence is "imprudance."

The correct spelling is "imprudence," which means a lack of caution or wisdom.

The other options, "conscience," "necessity," and "reprimanded," are spelled correctly and have the following meanings:

• Conscience: The inner sense of what is right or wrong in one's conduct or motives, impelling one toward right action.
• Necessity: The state or fact of being required or indispensable.
• Reprimanded: Criticized or rebuked formally or officially for one's actions.