Explanation:

Let’s break it down:

- A promissory note, by law, must include an unconditional promise to pay a certain amount of money only—not goods, not services, not a mix.

- Option 1: Pay Rs. 10 lakhs

This is a clear, straightforward promise to pay money, and that’s exactly what a valid promissory note needs.

- Option 2: Deliver certain goods

This isn’t valid. A promissory note is only about paying money, not delivering goods.

- Option 3: Pay Rs. 10 lakh and deliver certain goods

Nope, still not valid. Mixing goods and money makes it invalid as a promissory note.

- Option 4: Both (a) and (c)

Bringing in both of the above? Still incorrect due to the reasons above.

So the correct answer is Option 1: Pay Rs. 10 lakhs.