Final answer:
The correct syntax to declare a variable of class type College using its default constructor and assign it using an anonymous object is option B) College school = College();.
Step-by-step explanation:
To declare a variable of class type College using its default constructor and then assign the variable using an anonymous object, you should choose option B) College school = College();. This option creates a new College object and assigns it to the variable school in one statement, which is both efficient and clear in its intent.
Option A) is not the most efficient way to do this, as it declares the variable and then assigns it in two separate steps. Option C) and D) are not correct syntax in most programming languages for declaring a class type variable using its default constructor.
Therefore, the correct syntax is B) College school = College(); which uses the default constructor to initialize the school variable.