Which of these actions would decrease heat transfer between two objects?
increasing the temperature of the warmer object
increasing the area of their contact
reducing the thermal energy of the cooler object
reducing the time of their contact

The correct options are

When two objects are in contact with one another, heat is transferred from the hotter object to the cooler object which is called convection and this process  depends upon certain factors like the amount of temperature and the time of contact. When the area between two objects is increased the medium carry less amount of heat to the second object and most of the heat is lost in the way, Similarly when the time of contact is reduced then the same phenomenon occurs again and most of the energy is lost in air.

no theres only one correct answer and its D

electromagnetic shielding is the practice of reducing the electromagnetic field in a space by blocking the field with barriers made of conductive or magnetic materials. shielding is typically applied to enclosures to isolate electrical devices from their surroundings, and to cables to isolate wires from the environment through which the cable runs. electromagnetic shielding that blocks radio frequency electromagnetic radiation is also known as rf shielding.

the shielding can reduce the coupling of radio waves, electromagnetic fields and electrostatic fields. a conductive enclosure used to block electrostatic fields is also known as a faraday cage. the amount of reduction depends very much upon the material used, its thickness, the size of the shielded volume and the frequency of the fields of interest and the size, shape and orientation of apertures in a shield to an incident electromagnetic

from wikipedia