Which of the following examples best classifies as 'exercise' rather than just 'physical activity'?

Standing and shifting weight occasionally while talking on the phone, performed every day but without a structured plan or progressive goals.

A 30-minute planned jog at a steady pace with the intent to improve aerobic endurance.

Unstructured wandering through a museum for 45 minutes without a targeted intensity or intention to improve a fitness component.

Carrying groceries from the car to the kitchen three times a week without any change in intensity or plan and without progressive overload.