What is a key characteristic of the decrease$-$by$-$one variant in decrease$-$and$-$conquer algorithms?

Please be aware that there will be point deductions for incorrect answers.

The problem size is reduced by a constant factor in each iteration.

The algorithm employs a dynamic programming approach.

The algorithm typically involves iterative deepening.

The size of the problem is reduced by exactly one in each step.

The algorithm often uses a greedy approach for problem$-$solving.

The solution involves transforming the problem into a different representation.