Which statement is true about nested if-else structures?

The question asks which statement is true about nested if-else structures.

• A. They must always use curly braces: This is not true for all programming languages. For example, Python uses indentation, and in languages like C++ or Java, curly braces are optional if the if or else block contains only a single statement.
• B. They allow more complex decisions: This is correct. Nested if-else statements enable you to check multiple conditions in a hierarchical manner, leading to more intricate decision-making logic within a program.
• C. They only work with integers: This is incorrect. If-else statements can evaluate conditions involving various data types, including strings, booleans, and floating-point numbers, not just integers.
• D. They cannot contain logical operators: This is incorrect. Logical operators (like AND, OR, NOT) are commonly used within the conditions of if-else statements to combine multiple expressions.

Therefore, the true statement is that nested if-else structures allow for more complex decisions.

The correct option is B.
B) They allow more complex decisions.