Answer: handpicking method
2. Difference in size.
Explanation: The method in which substances in a mixture can be separated by just picking them with the help of hand from the mixture is known as handpicking method.
It is one of the methods which can be carried out for mixture of dry substances.
As the size of cereal bits and marshmallows is significantly different, he can handpick the larger chunks of marshmallows and separate them from the smaller sized cereal bits.