The following chart shows the sales (in thousands) of pens, pencils and books in month1, month2 and month3. Answer the question based on the chat.
| Month1 | Month2 | Month3 | |
| Pens | 5.6 | 4.9 | 4.6 |
| Pencils | 6.7 | 7.3 | 6.2 |
| Books | 4.5 | 5.7 | 6.3 |
Which product has the highest sales in all 3 months?
1
None
2
Books
3
Pens
4
Pencils