Gravitational attraction is determined by the mass of the object. The object with the greatest gravitational attraction toward the center of the Earth in your list is the 1,500-kilogram truck.
The gravitational force can be calculated using the formula \( F = mg \), where \( F \) is the gravitational force, \( m \) is the mass of the object, and \( g \) is the acceleration due to gravity (approximately 9.81 m/s²). Therefore, the truck has the greatest gravitational force due to its larger mass compared to the other objects listed.