There are multiple answers you can tell your interviewer:

I will drop it from 1cm. Or
I will put multiple layers of bubble wrap around it and drop it on the concrete floor. Or
I will dip it in vinegar for 2 two days, which will make the eggshell flexible and post that I will drop it on the solid floor. Or
Concrete floors are tough to crack.

BY Best Interview Question ON 08 Oct 2020