Answer:
The answer is : 1. underproduced.
Explanation:
Products with positive externality are products whose consumption will benefit not only the consumer but the third-party/the whole society as a whole (e.g: education, healthcare)
The problems with positive externality is the third-parties who benefit from the product consumption do not pay for the product; thus, the product's suppliers can not priced-in all the product benefits.
As a result, supplies usually produced less than the optimal level leading the products entailing positive externality underproduced.
So, 1. underproduced is the correct choice.