Explanation:

Let’s break it down:

- Option 1: 15

Not correct. India had 15 High Courts several decades ago, but more have been added since.

- Option 2: 21

Also not correct. This number was accurate a few years back, but the number has changed.

- Option 3: 16

Still off. This was true way back, before several states and union territories got their own High Courts.

- Option 4: 25

This is the correct answer. Right now, India has 25 High Courts, each serving one or more states and union territories.

So, here’s what this really means:

- High Courts are set up as and when new states or union territories need them.

- The total has shifted over the years, with the latest courts established in places like Andhra Pradesh and Telangana.

- The answer you’re looking for right now is 25, not 21.