4. Give reasons:
a. We use tongs to catch a burning piece of a coal.

Tongs are a type of tool used to grip and lift objects instead of holding them directly with hands. ... Common fire-tongs, used for picking up pieces of coal and placing them on a fire without burning fingers or getting them dirty are of this type.

that wouldn't exactly do anything. if people have no idea what app you're using and also don't really care, then they won't/can't do anything against them.