The coefficient of areal expansion measures the change in area of a material per degree of temperature change. In this case, the coefficient of areal expansion is given as 1.6 x 10-5 K-1.

The coefficient of volume expansion, on the other hand, measures the change in volume of a material per degree of temperature change. To determine the coefficient of volume expansion from the coefficient of areal expansion, we can use the relationship:

Coefficient of volume expansion = 2 * Coefficient of areal expansion

Using the given coefficient of areal expansion of 1.6 x 10-5 K-1, we can calculate the coefficient of volume expansion as follows:

Coefficient of volume expansion = 2 * 1.6 x 10-5 K-1

= 3.2 x 10-5 K-1

Therefore, the correct answer is option 3: 3.2 x 10-5 K-1.