Motion of a train is an example of________.

CONCEPT:

• Rotatory Motion: Rotational motion or circular motion, is a physical motion that happens when an object rotates or spins on an axis. Example: Rotation of a fan.
• Spin Motion: Motion of an object as it rotates around the axis through its center of mass. Example: Rotation of a top.
• Projectile motion: Projectile motion is the motion of an object projected into the air, under only the acceleration of gravity. The object is called a projectile, and its path is called its trajectory. Example: a cannonball fired at some angle.
• Translatory motion: Motion with a fixed direction of
  the net force.All the particles of a body executing translatory motion move in the same direction traversing parallel paths. Example: the motion of bus or train.

EXPLANATION:

• The motion of an object is said to be translatory if the position of the object is changing with respect to a fixed point or object. So the motion of train is an example of translatory motion.

So option 4 is correct.