Imparting heat to the system will lead to:

1. Increase in entropy:
When heat is added to a system, the internal energy of the system increases. This increase in energy leads to an increase in the number of microstates available to the system. As a result, the system's entropy increases. Entropy is a measure of the system's disorder or randomness.

2. Increase in motion of molecules:
Heat is a form of energy that can be transferred from one object to another due to a temperature difference. When heat is added to a system, the kinetic energy of the molecules within the system increases. This increase in energy causes the molecules to move faster and collide more frequently. Consequently, the motion of molecules in the system increases.

Explanation:
- When heat is added to a system, the energy of the system increases. This increase in energy leads to an increase in the number of microstates available to the system. Microstates refer to the different ways in which the energy can be distributed among the particles in the system. The more microstates available, the higher the entropy of the system.
- By adding heat to the system, the molecules within the system gain more kinetic energy. This increase in energy causes the molecules to move faster and collide more frequently. As a result, the motion of molecules in the system increases.
- Both of these effects, an increase in entropy and an increase in motion of molecules, occur simultaneously when heat is imparted to the system. Therefore, the correct answer is option 'D' - Both 1 and 2.

Summary:
Imparting heat to a system leads to an increase in entropy and an increase in the motion of molecules within the system. The increase in entropy is due to the increase in the number of microstates available to the system, while the increase in motion of molecules is a result of the added heat energy. Both of these effects occur simultaneously when heat is added to the system.