Answer:
A. Heat flows from an object at higher temperature to an object at lower temperature
Explanation:
The option A obeys the 2nd law of thermodynamics. The heat will flow from the object at higher temperature to the object at Lower temperature till they reach an equilibrial state.
Heat doesn’t necessarily flow from an object with higher thermal energy to an object with lower thermal energy because an object has a higher thermal energy when it’s mass is more than the other. This makes B wrong.
C is wrong because heat moves from an object with higher temperature to objects with Lower temperature regardless of the state of matter.
A nuclear can hold 2 electrons
Answer:
So mass of the object will be 3.2 kg
Explanation:
We have net force on the object F = 16 N
Acceleration of the object 
We have top find the mass of the object
From newton law of motion we know that force is given by
F = ma , here m is mass and a is acceleration
So 

So mass of the object will be 3.2 kg
I think they can use more durable materials.