- More water droplets are present in the air after the rain
- Light refracts when it passes through water droplets
- So, light is more easily to be refracted after the rain

- Light is more easily to be refracted after the rain
- Refracting light causes light to split into different colors
- So, light is more easily to be split into different colors after the rain

- Light is more easily to be split into different colors after the rain
- A rainbow is formed by refraction of light by splitting light into all different colors
- Hence, a rainbow is more easily to be formed after the rain through light refraction

- A rainbow is more easily to be formed after the rain through light refraction
- Sunlight is a kind of light
- So, sunlight and rain can cause a rainbow

So, sunlight and rain can cause a rainbow
Q: Which pair together could cause a rainbow?
Context:
- More water droplets are present in the air after the rain 
- Light refracts when it passes through water droplets 
- A rainbow is formed by refraction of light by splitting light into all different colors 
- Sunlight is a kind of light 
- Refracting light causes light to split into different colors