The orbital overlapping is maximum in:

Explanation

To explain these we have to remember that P orbital has more directional nature and as orbital has non directional nature. So the P orbital has more effective overlap then that of the S orbital.

In the case of Cl₂ there is an overlap between two P orbital, therefore the overlap is more effective and maximum overlap.

But in case of Hl, HCl, HBr the overlap between the S orbital of hydrogen and P orbital of halogen. So overlap is not that effective and minimum overlap.

Final answer

Correct Option (A)