The mode is the value that appears with the highest frequency in a dataset. Counting frequencies: value 2 occurs 3 times; value 4 occurs 2 times; values 3 and 5 occur once each. Since 2 appears most frequently, the mode is 2.

The median is the positional middle value of a dataset. It is calculated by first arranging the observed data in ascending (or descending) order of magnitude and then locating the central observation.

Calculation of statistical mode:

• The mode is defined as the value that occurs with the highest frequency in a data set.
• In the given dataset ($-18, -13, 0, 16, 3, -15, 0, 11, -14, 0, 12$), the number $0$ appears 3 times, whereas every other number appears only once.
• Since $0$ has the highest frequency of occurrence ($3$), the mode is $0$.
• Therefore, option 1 (0) is the correct answer.