Which conclusion can be logically drawn from the statements given below?
Statements:

1. All crows are birds.
2. All peacocks are crows.
Conclusions:

I. All peacocks are birds.
II. All birds are peacocks.

1. All crows are birds.
2. All peacocks are crows.

I. All peacocks are birds. (True, since all peacocks are crows and all crows are birds, it follows that all peacocks are birds).
II. All birds are peacocks. (False, only peacocks are included within crows and birds, but not all birds are necessarily peacocks).

Thus, correct option is (d).