Please read the following table in Markdown format and then answer the question according to the table. Table cells in one row are seperated by '|', and different rows are seperated by '
'.

Table:
|  | DEVICE A simple mechanical device |  | FUNCTION What the device is meant to be used for |  | EXAMPLE A concrete example of the device in use |
| --- | --- | --- | --- | --- | --- |
| A | thermometer | is used for | measuring temperature | ; for example, | measuring the body temperature of a sick person |
| A | hand lens | is used for | viewing small objects | ; for example, | looking at small white spots on leaves |
| A | graduated cylinder | is used for | measuring liquid volume | ; for example, | measuring a dose of liquid medicine |
| A | balance | is used for | measuring weight | ; for example, | measuring the weight of a rock |
| A | bar magnet | is used for | moving objects containing iron | ; for example, | separating iron filings from sand |
| A | inclined plane | is used for | moving objects up or down a slope | ; for example, | pushing a cart up a ramp |
| A | pulley | is used for | moving objects straight up or down | ; for example, | moving a flag up or down a flagpole |
| A | lever | is used for | moving heavy obects a short distance | ; for example, | prying a heavy rock out of a shallow hole |
| A | balance | is used for | comparing two small masses | ; for example, | comparing the masses of two small rocks |
| A | ruler | is used for | measuring length; measuring size; measuring distance | ; for example, | measuring the length of a desk |
| A | measuring cup | is used for | measuring liquids and powders | ; for example, | measuring a quantity of water |
Question:
"What mechanical device would you use to compare two small masses; for example, comparing the masses of two small rocks?" Select the correct choice to answer the question or fill in the blank.
Choices:
(A) A ruler
(B) A balance
(C) A thermometer
(D) A graduated cylinder
Answer:
(B) A balance