Which of the following is an integer? (Select the two best answers.)

An integer is a whole number that can be either positive, negative, or zero. In this case, the number 16 is a clear example of an integer as it is a whole number without any fractional or decimal component. This fits the definition of an integer perfectly.

The choice of 00000001 also represents an integer despite being written with leading zeros. In mathematics, leading zeros do not change the value of a number; thus, 00000001 is treated the same as 1, which is indeed an integer.

Other options like "cat" and "string" are not integers as they are not numeric values. Instead, they represent types of data or text, which do not fit the criteria for integers. Understanding these distinctions is essential in recognizing different data types and their roles in programming and data management.