Q1: A pen shaped device which can sense light, and is used to point at spots on a video screen.

ANS:B - Light pen

We have mouse, by which we can click and open something.

We have Keyboard, by which we can write something.

But can we write it in our own handwriting, Can we sign on the computer using the mouse. NO.

When using a mouse in paint brush that time I felt that we need something which can be used as a pen.

That's why it is light pen.