Match List I with List II.
Choose the correct answer from the options given below:

List I	List II
a. If the implementation of generated or derived classes differs only through a parameter, we have	I. to use a class hierarchy
b. If the actual types of objects used cannot be known at compile time, we have	II. improved run-time efficiency
c. If inline operations are essential and templates are used, we have	III. to use templates
d. To gain access to differing instances of derived classes through a base, we have	IV. to use explicit casting

1. Aa-I, b-II, c-IV, d-III
2. Ba-III, b-I, c-II, d-IV
3. Ca-I, b-III, c-II, d-IV
4. Da-II, b-I, c-III, d-IV

Pick an option to check yourself, or open the answer below.