Which of the following strikes is suitable for the center of the abdomen?

The strike with an empty hand is suitable for the center of the abdomen because it allows for precision and control. Using an empty hand can target the softer areas of the abdomen effectively without risking injury to the person delivering the strike. This technique can be used in situations where a less aggressive response is necessary while still creating an impact that can momentarily incapacitate an opponent or divert their attention.

The empty hand strike can involve techniques such as an open-handed push or jab, which can disrupt an attacker's balance or posture. This method can be advantageous in self-defense scenarios, as it can be executed quickly and can minimize the risk of causing severe harm compared to strikes that involve more force, such as with a fist or knee.

Focussing on abdominal strikes is also tactically effective since the abdomen houses vital organs. An empty hand strike here can wind an opponent, potentially providing the defender with an opportunity to escape or gain control over the situation.