Final answer:
The var keyword allows a variable to change its value, but its type remains fixed.
Step-by-step explanation:
The correct answer is a) True.
The var keyword in programming languages like JavaScript allows a variable to change its value. However, the type of the variable defined with the var keyword is not flexible and remains fixed once assigned a value. In the example given, if the code contains a variable declared using the var keyword and the assigned value is incompatible with the declared type, the code will not compile and will result in an error.