Final answer:
With four variables in a truth table, there are indeed 16 possible combinations, as each variable can have two states (true or false). This is verified by calculating 2 to the power of the number of variables, which is 2^4 equals 16.
Step-by-step explanation:
The question relates to the number of combinations possible in a truth table with four variables. For each variable, there are two possibilities: true (T) or false (F). Therefore, with four variables, the number of combinations is calculated using the formula 2^n where n is the number of variables. In this case, n equals 4, so the number of combinations is 2^4, which is 16. Thus, the statement that the truth table for four variables has 16 possible combinations is true.