The correct option is B No
Carrying umbrella is not a good idea at all during thunderstorms.
As a lightning flash travels toward the ground from a nearby cloud, it looks for the tallest object. This is because all the objects attached to the ground acts as ground or earthed objects. So lightning takes the shortest path to travel and thus, falls on the tallest object. If you're holding an umbrella in an area surrounded by taller buildings, it's not so risky. But If you are the only tall object in the place surrounding you, the lightning flash will fall on you.
Thus, carrying umbrella is not a good idea at all during thunderstorms.