A. A class can have multiple default constructors. 17, Which one of the following statements is true regarding default constructors? A default constructor cannot be called implicitly. A default constructor can be implemented as a global function. An empty default constructor is provided automatically if no other constructors are specified. B. C. D. 18. Which one of the following statements isA. You can only have one destructor for a class false with respect to destructors? B. Destructors take no arguments. C. A destructor is a member function of a class D. A default destructor is not provided automatically 19. The constructors for objects at file scope A. before main begins B. immediately after main begins. C. as soon as code in that file is executed D. immediately before the object is first used. are called 20. Which one of the following statements is A. The y cannot create a new object using values from an true about copy constructors? existing one B. They cannot be called implicitly during initialization. C. They can be called explicitly. D. They can take any number of parameters. 21. What is printed by the following code? A. 10 B. 20 c. 30 D. 40 #include using namespace std: intx10 int main() int x-20; if (true) 30; int x40 cout