Which of the following is an impact of having a forward CG on aircraft performance?

Having a forward center of gravity (CG) typically leads to increased take-off and landing distances due to the aircraft being less responsive to control inputs. When the CG is forward, it raises the amount of control force required to achieve desired flight maneuvers. This results in a heavier feel during take-off and landing, which can translate to longer distances needed to achieve take-off velocity and become airborne, as well as longer stopping distances upon landing.

In addition to impacting take-off and landing distances, a forward CG can also reduce the aircraft's stability in certain conditions and make it less maneuverable during flight phases. The increased weight feeling during rotation combined with the reduced effectiveness of control surfaces can lead to less optimal climb performance and can also affect fuel efficiency.

The other options regarding climb gradient and rate of climb, reduced fuel burn and thrust required, and improved rotation and flare maneuvers, are typically associated with a more balanced or slightly aft CG, which provides better performance for those specific phases of flight. Therefore, the impact of a forward CG is accurately described as increasing take-off and landing distances, which is why this choice stands out as the correct answer.