Given below is a write-up on the discovery of the mouse, but the sentences are mixed up. What is the correct logical sequence?
I. We use the mouse not just because Engelbart invented it, but because it performed best versus other pointing devices.
II. Years later, while seeking a screen-selection device, he recalled these notes and, with Bill English, built the first mouse.
III. At a conference, he scribbled an idea about two wheels at right angles to track motion on a plane.
IV. The mouse won because it was easiest to use.
V. As a student he measured areas under curves with a device whose wheels rolled in one direction and slid sideways at $90^\circ$.
VI. Doug Engelbart tells how he invented the mouse.
Identify the option that will replace the question mark. 
Identify the option that will replace the question mark. 
An intersection is a point where two or more lines/curves meet or cross. How many intersections are there in the figure given below? 

The drawing shows the figure of a horse with the point (marked with a red dot) where the pelvic girdle meets the vertebral column. Which of the options shows simplified bone linkages for the hind leg of the horse beginning with the red dot? 



