This option is correct. If the difference between the variable borrows and the variable returns is 0, they must have the same value. This would indicate that each time the particular laptop was borrowed it was returned, which would indicate the laptop is not currently borrowed.
The expression (num greater than 15) or (num equals 15) evaluates to true if (num greater than 15) is true, or if (num equals 15) is true, or if both are true. The original expression (the expression in this problem) evaluates to true if numis greater than or equal to 15.
B is incorrect. Algorithm I does not work correctly when the maximum value is less than -1. Algorithm II works correctly in all cases.
C is incorrect. While statements II and III are correct, statement I is also correct because software simulations can usually be built before a prototype car.
C is incorrect. Some problems cannot be solved with an algorithm for all possible inputs.