Which of the following statements with regard to the phenomenon of the primary rainbow formation by water droplets is/are correct? 1. It involves refraction and one internal reflection of sunlight. 2. It involves refraction of sunlight only. 3. It is formed as the inner bow. 4. It may involve more than one internal reflection as well as refraction of sunlight. Select the answer using the code given below:

A primary rainbow is formed when sunlight undergoes refraction as it enters a water droplet, one internal reflection at the back surface, and then refraction again as it exits the droplet. This corresponds to statement 1. The primary rainbow appears as the inner (and brighter) bow when both primary and secondary rainbows are visible — confirming statement 3. Statement 2 is incorrect because internal reflection is essential. Statement 4 describes the formation of a secondary rainbow, not the primary. Therefore, statements 1 and 3 are correct.