Which musical device can composers use to lengthen a note by double? staccato tenuto marcato fermata rubato

The correct answer here would be fermata. This is a musical notation that is also known by numerous names such as a hold, a pause or my personal favorite the cyclops eye. This notation is used to indicate that a note should last longer than its normal duration. And that includes doubling its duration.

His contribution to the orchestral genre mainly lies with foreshadowing ideas that are to come like the emergence of the classical symphony, the cadenza for a keyboard, and paired instrumentation;

The answer is gladiators