Concept:
Motion refers to the change in position of an object with time. When an object moves along a straight path, the motion is called linear motion or rectilinear motion.
Different types of motion include:
• Linear motion -- movement along a straight line
• Rotatory motion -- movement around an axis
• Angular motion -- rotational movement through an angle
• Curvilinear motion -- movement along a curved path
Step 1: Identify the nature of the path.
The object is moving in a straight line.
Step 2: Determine the type of motion.
Motion along a straight line is known as:
\[
\text{Linear motion}
\]
Hence, the correct answer is:
\[
\boxed{(C)\ \text{Linear}}
\]