Match the items given in Column-I with those in Column-II and select the correct option given below:

Adult human RBCs are enucleated. Which of the following statement(s) is/ are the most appropriate explanation for this feature? 

1. Only (a)
2. (a),(c) and (d)
3. (b) and (c)
4. Only (d)

Serum differs from blood plasma in:

1. lacking globulins

2. lacking albumins

3. lacking clotting factors

4. lacking antibodies