Arepresentative in congress resigns from his office due to ill health, leaving his seat in congress vacant. in order to fill the vacancy, a(n) must be held.

Special election

Explanation:

A special election is an election conducted in the United State senate in order to fill the void seat made vacant when a senator dies or resign from office before the expiration of a six year tenure. Whoever wins the election will serve the remaining duration of the former office holder. It is also known as by-election, it was first developed in the 16th

century during the Reformation Parliament by Thomas Cromwell.